导图社区 语法
语法
你真的了解英语语法吗?你掌握了正确的学习英语方法了吗?本思维导图适应于初学者或需要系统学习英语、英语框架构建者。主要为基本语法，根据网课整理。希望对你有帮助!
编辑于2019-04-23 02:14:06- 句子组成
- 相似推荐
- 大纲
《骆驼祥子》思维导图
《红岩》思维导图
《老人与海》思维导图
《钢铁是怎样炼成的》章节概要图
《傅雷家书》思维导图
《西游记》思维导图
《水浒传》思维导图
《茶馆》思维导图
《朝花夕拾》篇目思维导图
《红星照耀中国》书籍介绍思维导图
组成句子的基本单位
词
名词
This book is boring. I want this book. My gift is a book. I find him a charming boy. It is an information technology book. I admire Steve Jobs, the founder of Apple. 名词可充当：宾语、主语、表语、定语、补语、同位语
名词单复数
要点1：不可数名词没有复数形式 information knowledge evidence advice behavior news research waste pollution There are evidences(改成is evidence) that rules can lead to children's anti-social behaviors.（×）
要点2：不可数名词要表达复数概念，可在前面加可数的量词 （pieces kinds categories levels）+of+不可数名词 These advices are valuable to you.（×） These pieces of advice are valuable to you. These kinds of pollution are extremely harmful. Poor water quality is responsible for health problem.（改成problrms） Many residential areas do not have the (去掉)fresh water. This is a (改成an)organization which profits from selling bottled water. Cities should supply water to every people.(改成all people 或 every person) Little progresses have（改成progress has） been made in this area. Less and less people(改成fewer and fewer people) read print books.
代词
I hate it. This is your car. I can solve this problem myself. 代词可充当：主语、宾语、表语、定语、状语
1.人称代词
主格
I/you/he/she/it/we/you/they
宾格
me/you/him/her/it/us/you/them
要点
要点1：学术写作，最好用第三人称，比较客观 避免用第二人称（you）
要点2：I（我）和其他名词作并列主语，I要放到and后面，表示谦虚 My colleagues and I will finish this project. Not only my colleagues but also I are hard-working.（×） （并列连词and、both...and...连接主语，谓语为复数；并列连词or、but、either...or...、neither....nor、not only...but also...连接主语，谓语要和靠近谓语的主语配合）
要点3：一个不清楚性别的名词单数，人称代词要用he or she This project needs a good manager. He or she should have relevant experience.
要点4：代词指代要明确 前一句如果出现2个复数名词，后一句用they指代，有歧义 Managers should help their subordinates because they can complete work well.（×） Managers can complete work well so they should help their subordinates.
2.物主代词
形容词性（放名词前，不能单独使用）
my/your/his/her/its/our/your/their
名词性（可单独使用）
mine/yours/his/hers/its/ours/yours/theirs
要点
要注意物主代词的人称、单复数配合； 注意区分形容词性物主代词和名词性物主代词 She lost her job. My job is easier than hers.=her job
3. 反身代词
myself/yourself/himself/herself/itself/ourselves/yourselves/themselves
注意和主语的人称、单复数配合 He needs to take care of herself.（×） 反身代词作宾语 They can achieve this target themself（×）反身代词作状语
4. 指示代词this（这个） that （那个） these（这些） those（那些）
要点1：指示代词=名词，可单独使用，充当主语、宾语、表语 指示代词可放名词前，充当定语 This is my favorite book. Tom and Jerry. I have never read this. Tom and Jerry. My favorite book is this. This book is my favorite.
要点2： this it的区别 都可指代前一句说过的单数名词 Tom and Jerry. It/This is my favorite book. 要指代前面说过的一句话，一整件事，只能用this 他每天做运动，这对他身体有好处 He does sports every day. This is beneficial to his health.
要点3：These those的区别 在作文里，these（这些）指代前一句说过的名词复数； those（那些）是之前没提过的 These products are common. 那些销售电冰箱的公司并不是很赚钱 Those companies which sell refrigerators are not very profitable. =The companies which sell refrigerators are not very profitable.
5.不定代词anybody anyone somebody someone everybody everyone 都是单数
要点1：注意主谓的配合、代词的单复数配合 Anybody who do (改成does)not save money for their retirement will have a lower standard of living.（×） Mary set up a business in 2000. Hers(改成her) company went bankrupt two years ago. 这家公司注重客户服务。他们的市场份额正在增加 This company pays attention to customer service. Their(改成it's) market share is increasing. 这个超市和几个供应商都敲定了买卖，这对于他们的发展很重要 This supermarket has done a deal with several suppliers. It( 改成this) is important to their development. They carry out market research themself.(改成themselves)
形容词/副词
This special activity is highly popular. Exams make me sad. I study English happily. 形容词可充当：表语、补语、定语 副词可充当：状语
比较级/最高级
形容词和副词有比较级（更...)和最高级(最...)
要点1：避免more和er两种形式同时出现 Toys can make children more happier.(×)
要点2：比较级前可加副词，表示程度“大得多”“远远更大”“大一点点”
差异大 much/far/remarkably/significantly/considerably
差异小 slightly/a little/a bit
要点3：部分形容词、副词（本身包含最高级的意思），没有比较级和最高级：perfect, superb（极好的）,excellent（优秀的）, noble, extreme（极端的）, sublime（卓越的） His English is more perfect than mine.（×）
比较结构有两种
一：than引导的一般比较结构 He is more prudent than Peter He is more prudent than Peter is prudent. 比较状语从句 避免重复，从句去掉重复部分，保留比较对象 He works harder than Peter. He works harder than Peter works hard. 比较状语从句 He can work longer than Peter . He can work longer than Peter can work long. 比较状语从句
要点1：部分情况（句子有多个名词），从句的系动词、助动词、介词不能省，避免歧义 这本书在男生当中比在女生当中受欢迎 This book is more popular in boys than this book is popular in girls. This book is more popular in boys than girls.（×） This book is more popular in boys than girls are popular in boys. 这本书比女生们更受男生欢迎（男生更喜欢这本书，不太喜欢女生） This book is more popular in boys than in girls. 我比我的老板更熟悉这个团队 I am more familiar with this team than my boss is familiar with this team. I am more familiar with this team than my boss（×） 我熟悉这个团队多过熟悉我的老板 I am more familiar with this team than my boss is （√）
二：as...as...引导的原级比较结构 My time is as valuable as your time is valuable. 比较状语从句 My time is as valuable as your time.=as yours 避免重复，从句去掉重复部分 He runs as fast as John runs fast. 比较状语从句 He runs as fast as John.
要点2：比较结构的名词重复了，可用代词that、those指代代替 A的B 与 C的B比较 这家公司的产品比其他国家的产品要好 The products of this company are better than those of other countries. 他的资历和另一个候选人的一样好 His qualification is as good as that of another candidate.
要点3：“比...少” “没有...那么” 多音节单词：less+形容词/副词原形 This book is less expensive. He studies less carefully. This book is the least expensive. 单音节单词：not as+形容词/副词原形 as 他的房子没你的大 His house is not as big as yours=your house.
要点4：表达“越来越...” 单音节单词：比较级 and 比较级 This house becomes bigger and bigger. 多音节单词：more and more+形容词/副词原形=increasingly+形容词/副词原形 Swimming becomes more and more popular. Swimming becomes increasingly popular.
倍数
静态倍数：（同一时间）两个不同对象的倍数比较 A 是B的...倍 这个房子是我的房子的三倍大
一：倍数+比较级+than This house is three times bigger than mine. 二：倍数+as+原形+as This house is three times as big as mine. 四倍：four times 五倍：five times 注意：两倍 two times（×）twice
动态倍数：自身倍数的变化（不同时间） 新房子的数量在去年上升了三倍
一：increase/rise/grow+数字+fold three-fold/four-fold adv The number of new houses increased three-fold last year. 二：特殊的动词 double/triple/quadruple vi 上升了...倍 The number of new houses tripled last year. 三：数字+fold 当定语 three-fold/four-fold adj There was a three-fold increase in the number of new houses last year. The number of new houses experienced a three-fold increase.
注意：下降不能用倍数 20-10 The number of new houses in 2001 became a half of that in 1991. 30-10 The number of new houses in 2001 became one third of that in 1991. 分数表达：分子（基数词）+分母（序数词） 1/4 one fourth
区分形容词和副词
我们应该友好地和外国游客沟通 We should communicate with foreign visitors friendly. 我们都有可能犯错 All of us likely make mistakes. 政府需要快速做出一个决定 The government needs to make a decision fastly. 小孩必须努力地学习 Children must study hardly.
动名词
Reading books is a good habit. I like reading books. One of my hobbies is reading English books. 动名词可充当：主语、宾语、表语
不定式
I want to read books. To read books is important. My job is to recruit new members. This book has enabled me to pass the exam. I have an opportunity to write a book. I wrote several books to help students. 不定式可充当：主语、表语、宾语、宾补、定语、状语（目的）
区分不定式作宾补、定语、状语（目的）
不定式作宾补，为固定表达，不可省 不定式作宾补:逻辑主语是宾语，宾语和宾补之间有主谓关系 I allow him to study abroad.
接不定式做宾补的常用动词表！记忆！
不定式作宾语的定语:宾语和定语之间不是主谓关系，可省 The ability to learn is important. I need an opportunity to study abroad. I have a task to finish.
不定式作目的状语:修饰句子，逻辑主语是句子的主语，可省 I study hard to get the scholarship. I study English to get more job opportunities.
现在分词/过去分词
I like interesting books. This book is interesting. Music makes your life interesting. Traveling makes me tired. 分词可充当：表语、补语、定语
介宾短语
I am in China. I work in China. The environment in China is not so good. Bilingualism can put you in a advantageous position. 介宾短语可充当：表语、补语、定语、状语 in, at, with, for, despite, due to, because of
区分介宾短语---补语、定语、状语
补语：不可省，宾语是其逻辑主语 定语：可省，修饰名词，该名词是其逻辑主语 状语：可省，修饰句子动作发生的状态，句子主语是其逻辑主语 Students should study with confidence. Teachers prefer students with confidence. I like the exhibition in this museum. I call my teacher for getting more advice.
谓语动词
动词分类： 主动词：及物动词、不及物动词 助动词 情态动词 系动词
情况1：主动词
不及物动词（组） The figure increased from 1991 to 2001. He comes here every Monday. Many wild species died out last year.
及物动词 （组） I appreciate him. We talked about him last night.
情况2：助动词+主动词
助动词：辅助主动词，表达否定、时态、语态，没有实质意思，不能单独使用
1) have/has/had +过去分词：完成时
I have finished my homework. I have not=haven't finished my homework. I had finished my homework before you came.
2)do/does/did
+not表一般现在时/一般过去时的否定 Many boys like playing games. Many girls do not=don't like playing games. I liked playing games but now I don't. 一般过去时否定？ I have a car. I had a car. 否定？ I have not a car? I had not a car? 我已经有这本书了？ We do business with him. 否定？ We do not business with him?
放主动词前表强调 “确实...真的...” I do like playing games. I did see her in the library last week.
3)be(is am are was were been)
be+现在分词，进行时 “正在...” He is cleaning his room. We were sleeping when she came. I have been reading this book for two days. I am criticized by my parents. I was criticized by my parents last month. I critized my parents. 区分动词的过去式，动词过去式的被动
注意NB：区分系动词be和助动词be
系动词be 表“是...” ，后面接表语：说明主语的特点（身份、性质、特征） My hobbit is reading books. He is excited.
助动词be，单独没有意思，搭配分词，作谓语 助动词be+现在分词：表达进行时态，主语是动作的发出者 He is crying. He is watching TV. 助动词be+过去分词：表达被动语态，主语是动作的承受者 She is often praised by her teachers. This house was sold.
情况3：情态动词+主动词原形
can/could may might will would should must 情态动词无人称变化，部分有时态变化，表达一种情绪态度、推测可能性
can/could的区别
1)can表现在“可以，能够”；could表过去“可以，能够” You can buy this book for a dollar. You could buy this book for a dollar ten years ago. 2) “可能” can可能性>could，could表不太确定，更委婉 The crime rate can decrease if the government takes action in time. The crime rate could decrease if the government takes action in time.
will would的区别
1)will表一般将来时；would表过去将来时 “将..” I will graduate in June. I thought I would graduate in June.（实质上木有） 2)表主观推测 “就会...” If art galleries are free, more people will go there. If art galleries are free, more people would go there.（更委婉，主观推测） If you worked hard, you would pass the exam.（现在的虚拟，不可能发生
其他情态动词
没有人称变化，后面加动词原形 ought to=should had better used to You had better take a rest. 你最好不要休息？ We used to eat out on Sunday. 我们过去不常出去吃？
注意：
注意NB1： need dare既可以是主动词，也可以是情态动词 作情态动词（否定）+动词原形 无人称变化，dare可变过去式，否定直接后加not need not/needn't do sth. dare not =daren't do sth. dared not do sth. 作主动词+不定式作宾语 有人称、时态变化，否定需要助动词体现 need to do sth I need to relax. I needed to relax. dare to do sth He dares to cheat. He dared to cheat. 聪明的学生不需要做很多练习 我不敢换工作
注意NB2:半助动词（半情态动词） 情态动词：后面加动词原形，有具体意思 助动词：有人称、时态变化 have to、tend to、happen to、be able to、be willing to、be likely to、be going to、be about to He has to get up early tomorrow. We were just about to leave when Jerry arrived. 昨天，我们碰巧遇到老顾了
情况4：情态动词+助动词原形(have/be)+主动词
could/should+have done 原本可以做但没有做的事情，表抱怨、惋惜
could+have+过去分词 “本可以...” You could have told me the truth. should+have+过去分词 “本应该...” You should have brushed your teeth. must+have+过去分词 “一定是做了....” 很确定的猜测 You must have drunk beer. can/could/may/might/must+be+现在分词 正在做某事的可能性 They can be sleeping now. He must be sleeping now. can/could/may/might/must+be+过去分词 You might be dimissed if you are late. 被..的可能性
时态
通过主动词、助动词的变化来体现时态的变化 16种时态，四大类：过去时、现在时、将来时、过去将来时
一般时态 1.一般现在时 2.一般过去时 3.一般将来时
一般现在时
描述一个习惯动作、客观规律或者普遍的事实
主语为复数
肯定
1）谓语动词用原型 I watch TV every night. Many boys prefer science.
2）系动词：搭配主语am，are I am an adult. We are from China.
否定
1）谓语动 don't+词用原型 I don't enjoy reading. Many children don't like reading.
2）系动词：am not，are not
主语为单数
肯定
1）谓语动词+s,+es She knows me.
主语为第3人称单数，一般现在时肯定+es的动词： 动词以s、x、sh、ch、o结尾 pass-passes fix-fixes wash-washes watch-watches go-goes 辅音+y结尾的动词，要把y变成i，+es study-studies
2）系动词：is He is retired.
否定
1）谓语动词does not+动词原形 She doesn't know me.
2）系动词：is not He is not retired.
一般过去时
描述过去发生的事情（现在已经不发生了）一般会有一个具体的过去时间：...ago(2 days ago);last...(last year), yesterday, in the past
辅音+y结尾的动词，要把y变成i，+ed,变过去式 study-studied
一般将来时
将来要发生的事情
be going to+动词原形 也能表一般将来时,表示按计划将要做..., “计划做，打算做...” 第1人称单数：I am(not) going to study IELTS. 第2人称、第1、3人称复数：You/We/They are(not) going to study IELTS. 第3人称单数：He is(not) going to study IELTS.
will也表示一种主观猜测、主观观点（大作文） “会...” 如果学生可以出国留学，他们会有更多机会 If students can study abroad, they will have more opportunities. If museums become free, more people will go there.
一般过去将来时
在一个过去情景下讲述将来要发生的事情 一般用在宾语从句，主句用一般过去时,从句的将来时要用过去的将来
would也表达一种主观猜测、主观观点（大作文）“会...” I think strict discipline would have an adverse impact on children. 我认为严格的纪律会对孩子不利
would可用于表达现在的虚拟（不可能发生的） If all species died out now, human would suffer huge disasters. 如果所有物种现在都灭绝，人类会遭受巨大的灾难
进行时态 be+doing（现在分词） 1.现在进行时 2.过去进行时
现在进行时 be(am/is/are) doing（现在分词） “正在...” 常搭配的时间状语：at the moment, at present, currently, now,still
第1人称单数：I am (not)reading this book 第2人称、第1、3人称复数：You/We/They are(not) reading this book. 第3人称单数：He is(not) reading this book
常用于描述一种趋势、发展、变化（大作文的首段，背景描述） The Internet is changing our life. Pollution is getting worse and worse.
过去进行时 be(was/were) doing（现在分词）: 过去某一刻正在做某事，后面往往出现一个具体的过去时间点:at the time of..., when+具体的很短的时刻（when she left)
第1、3人称单数: I(He/She/it) was(not) reading a book when he came. 第2人称/第1、3人称复数: You/We/They were(not) reading a book when the accident happened.
和一般过去时的区别：
1)一些表状态的动词，没有进行时态:like,hate,love,enjoy,prefer,regret,agree,disagree,hope, wish,know, realize,resemble, belong to, own,smell,taste
2)过去进行时会有一个很短的过去时间表达，表示在过去那一刻正在做... When they were little, they liked games. She was studying when Tom arrived. At the time of robbery, they were sleeping.
完成时 have+done（过去分词） 1.现在完成时 2.过去完成时 3.过去将来完成时
现在完成时 have/has+done（过去分词） 强调一个已经完成的动作，对现在的影响 或强调一个动作从过去延续到现在 常搭配的时间状语：already,ever,never,yet,since+过去时间(last week/I was a child)，over/in the past...（few years/few decades/two years),up till now,so far, recently, lately
子主题
子主题
语态
主谓一致
从句
名词性从句
可充当成分
主语
This book is interesting. What I am reading is interesting.
宾语
I don't know this book. I don't know whether this book is interesting.
表语
His opinion is a good example. His opinion is that people should read more books.
同位语
I love the novel,The Old Man and the Sea. I love the saying that love heals all wounds.
句子的分类
陈述句
that+完整陈述句 区分：that引导的名词性从句 & that引导的定语从句 that引导的名词性从句，（不包括that）从句本身是完整的句子 （英语很重要）是毋庸置疑的事实 （That English is important） is an undouted fact. that引导的定语从句，（不包括that）从句本身不完整，缺主语或者宾语 人们偏爱（提供好的升职机会的）公司 People prefer companies that offer good promotional opportunities. People prefer companies that（ they去掉） offer good promotional opportunities.
1）陈述句当主语从句
避免头重脚轻，that引导的主语从句会用it代替 it放在主语的位置，作形式主语，没有实质意思，真正的主语是后面that引导的主语从句 It is important that the government develops public facilities. =It is important for the government to develop public facilities. it is...that+完整的从句
结构1：it's+形容词+that
ture/dear/obvious/apparent/important/imperative/likely
显而易见的是，空气污染对我们身体有害 It is apparent that air pollution is harmful to our health. 确实，贫穷会威胁社会稳定 It is ture that poverty can threaten social stability.
结构1：it's+过去分词+that
said/reported/argued/(widely)believed/well known/proven
人们普遍认为，贫穷会威胁社会稳定 It is widely believed that poverty can threaten social stability. 据说，过多的压力会导致一些严重疾病 It is said that too much pressure can lead to some serious diseases.
结构1：it's+名词+that
a pity/a shame/common knowledge/a pleasure/a fact
你不能来是一个遗憾 It is a pity that you cannot come.
2）陈述句当表语从句
that 引导的从句放在系动词be后面 吸烟的主要问题是（它对我们的肺部有害） The main problem of smoking is that it is harmful to our lungs. 学习外语的一个好处是（学生可以和外国人交流） One advantage of learning foreign languages is that students can communicate with foreigners.
3）陈述句当宾语从句
结构
情况1：放在动词后(think/believe/argue/agree/know/realize that+句子)
我觉得(教育对一个人的职业有很大影响) I believe that education has a huge impact on one's career.
情况2：放在特定形容词/过去分词后(sure/certain/glad/afraid/aware/worried/concerned/pleased)
我很确定(教育对一个人的职业有很大影响) I am sure that education has a huge impact on one's career.
注意
注意1：that引导的名词性从句不能放在介词后面
很多人没有意识到他们有音乐天赋 Many people do not realize that they have musical talent. Many people are not aware of that they have musical talent.(X) 父母很害怕（他们的孩子可能会遭受欺凌）（bullying) Parents are afraid that their children may suffer from bullying. Parents are afraid of that their children may suffer from bullying.(X)
注意2：that引导宾语从句，that可以省略 I think (that) museums should be free.
其他省略that的从句情况 that引导定语从句，先行词在从句中当宾语，that可以省略 （我喜欢的）那辆车是红色的 The car I like is red. The car is red. I like the car. 先行词是way，定语从句的that可以省略 我讨厌（他处理这个问题的）方式 I hate the way he handled this problem.（√） I hate the way. In this way, he handled this problem. I hate the way(that/in which)he handled this problem.（√）
情况3：宾语从句前的谓语表建议、命令（suggest/advise/demand/order），从句谓语用should+动词原形，should可以省略
They demand that the government (should)release all prisoners. Scholars advise that young people (should) be independent as soon as possible.
4）陈述句当同位语从句
放在一个名词后面，解释这个名词的具体内容、含义 后面会用同位语从句的常见名词：fact/idea/news/question/suggestion/view/message due to the fact that+同位语从句=because 状语从句
注意1：problem、proposal、trend、phenomenon、situation、result后面不能加that引导的同位语从句 我们应该留意（很多孩子营养不良）这个问题 We should pay attention to the problem that many children are malnourished.（×） Many children are malnourished. And we should pay attention to this problem. They couldn't accept the result that they lost the game.
注意2：区分that引导的定语从句 I agree with the idea that science is important. 同位语从句： that后面的从句是完整的 I agree with the idea that Tom offered. 定语从句：that后面的从句不完整，缺主语/宾语
一般疑问句
whether/if “是否”+完整陈述句 Should students do extra homework to improve grades? This has caused a heated discussion. （Whether students should do extra homework） has caused a heated discussion.
1）一般疑问句当主语从句 Whether students should do extra homework has caused a heated discussion.
2）一般疑问句当宾语从句
情况1：放在动词后(think/believe/argue/agree/know/realize)
我不知道(学生是否应该做额外的) I don't know whether students should do extra homework or not.
情况2：放在特定形容词/过去分词后(sure/certain/glad/afraid/aware/worried/concerned/pleased)
我不确定(学生是否应该做额外的) I am not sure whether students should do extra homework or not.
情况3：放在介词
人们对于(学生是否应该做额外的作业)有一个大讨论 People have a big argument about whether students should do extra homework.
3）一般疑问句当表语从句 Parents' concern is whether their children suffer from bullying.
4）一般疑问句当同位语从句 Many graduates face the problem whether they should continue studying.
注意
whether 和if的区别 1.只有if可以引导条件状语从句，“如果” 2.引导名词性从句，“是否”：if只能引导宾语从句，whether没有限制 3.从句后面要加or not/or+选项，只能用whether引导 I don't know whether (or not) students should do extra homework (or not). I don't know whether students should do extra homework or do less homework.
一个问题是（年轻人是否可以通过出国留学提高独立性） One question is（ that去掉） whether young people can improve independence by studying abroad. 注意：that和whether不能同时出现
特殊疑问句
特殊疑问词+陈述句
1）when/where/why引导的名词性从句本身是完整的句子
When he wrote this book is an interesting question. One question is where he wrote this book. I do not know why he wrote this book. We are confused about the question when he wrote this book.（同位语）
注意：when/where/why引导的从句要用陈述语序，不用倒装 Where did he write this book is a question.（×） One question is when can he write this book.（×）
2）how引导的名词性从句
结构
"如何、怎么样"-方式方法 how+完整句子
I don't know how this company can make profit.
"多么地..."-程度 how副词+完整句子
Some students don't know how efficiently they can finish this task. 从句还原：They can finish this task efficiently.(主谓宾状)
"多么的..."-程度 how形容词+主语+系动词
Some people don't realize how important water is. 从句还原：Water is important.(主系表)
注意：how引导的名词性从句是陈述句语序，不用倒装 很多人不知道水污染有多严重 Many people do not know how serious is water pollution.（×）
3）what/which/who/whom引导的名词性从句，从句要连带引导词才完整
结构
who
在从句中作主语 The police tried to figure out who committed this crime.
在从句中作表语 The police tried to figure out who he is. 从句还原：he is who.
whom
whom在从句中作宾语 The police tried to figure out whom he killed. 从句还原：he killed whom.
what/which
在从句中作主语 Many children don't know what is right or wrong.
在从句中作宾语 People do not know what they can do to alleviate pollution. 从句还原：they can do what to alleviate pollution.
在从句中作表语 I wonder what it is. 从句还原：it is what.
what/which+名词，引导名词性从句 , “什么样的....”（what在从句中作定语） The government does not know what/which policy it can implement to alleviate pollution. 从句还原：it can implement what/which policy to alleviate pollution.
注意
what/which/who/whom/when/where/how（why除外）引导的名词性从句，从句和主句主语一样，可以简化成what/which/who/whom/when/where/how to do Students do not know how they can finish assignment efficiently. Students do not know how to finish assignment efficiently. Students do not know where they can find relevant materials. Students do not know where to find relevant materials. 学生不知道他们能做什么为了通过考试 Students do not know what they can do in order to pass the exam. Students do not know what to do in order to pass the exam.
总结
that/whether/when/where/why后面引导的名词性从句自身是完整的 what/which/who/whom后面引导的名词性从句自身是不完整的，缺主语或宾语或表语 how 表“如何、怎样”，后面引导的名词性从句自身是完整的 how+副词，表“多么地...”，后面引导的名词性从句自身是完整的 how+形容词，表“多么的...”，后面引导的名词性从句自身是不完整的，缺表语 学者们正在讨论（严厉的刑法多么的有效） Scholars are debating how effective harsh sentences are.
定语从句
一个句子来修饰前面的名词（先行词），类似于形容词---形容词从句 形容词作定语：I like diligent people. 我喜欢勤奋的人 句子作定语：I like people who work hard. 我喜欢（努力工作的）人 I like people. They work hard. I like people who work hard. 先行词 关系词 先行词：被定语从句所修饰的名词 关系词：1.连接作用：放到先行词后面，连接主句和从句 2.代词作用：指代先行词，在定语从句充当一个成分（主/宾/定/状）
关系词
关系代词:which/that/who/whom/whose
先行词指人 在从句充当主语/宾语 ：who/whom
在从句充当主语 ：who （住在隔壁的）女人是一个著名的舞蹈家 The woman is a famous dancer. She lives next door. The woman who lives next door is a famous dancer.
在从句充当宾语 ：whom 我有一个（我可以完全信任的）朋友 I have a friend. I can trust him completely. I have a friend whom I can trust completely. 关系代词指代先行词，在从句作动词后的宾语 这是（和我一起工作的）同事 That is the colleague. I work with him. That is the colleague whom I work with . 关系代词指代先行词，在从句作介词后的宾语
先行词指物 在从句充当宾语/主语 ：which/that
只能用that不能用which
1）先行词有序数词 The first thing that you should buy is a car. 2）先行词有最高级 This is the most interesting story book that I have ever read. 3）先行词既有人又有物 We admire the scientist and his achievements that you told us. 4）先行词是代词:anything, everything, something, nothing You should tell me anything that you know. 5）先行词有不定限定词：all, every, any, little, few, no, none, much There is little work that is fit for you. 6）先行词有：the only/the last/the very/the one This is the only book that I like.
只能用which不能用that（除了这些情况，先行词指“物”都用that）
1）非限定性定语从句（主句和从句用逗号隔开） He is clever, which makes his parents happy. 2）先行词有those修饰 Students should avoid those activities which may distract them. 3）先行词在从句当介词后的宾语，介词提前到关系代词之前形成“介词＋关系代词” （我们住的）房子很大 The house is very large. We live in this house. The house that/which we live in is very large.（√） The house in which we live is very large.（√） The house in that we live is very large.（×）
先行词指物/人 在从句充当定语 ：whose
我认识一个（他的工作是教法语的）朋友 I know a friend. His(=a friend's) job is teaching French. I know a friend whose job is teaching French. （工作很稳定的）员工也会有压力 Employees feel stressed. Their(employees') jobs are secure. Employees whose jobs are secure feel stressed.
关系副词:where/when/why
指代的先行词在从句里面当状语 在从句中当地点状语 where 在从句中当时间状语 where 在从句中当原因状语（the reason）why
这就是（我第一次遇见你的）那间图书馆 This is the library. In this library, I met you for the first time. This is the library where I met you for the first time. 你应该记录一下（你开始工作的）那一天 You should record the day. In this day, you start working. You should record the day when you start working. 这就是（为什么孩子很暴力的）原因 That is the reason. For this reason, children are violent. That is the reason why children are violent.
注意
要点1：先行词要紧挨着定语从句，不能隔开
（资金短缺的）公司一般会辞退一些员工 Companies normally dismiss some workers which have financial problems.（×） Companies which have financial problems normally dismiss some workers . 先行词 关系词
要点2：主句要完整，从句要完整（基本成分不多不少）
The woman who she lives next door is a famous dancer. （×） I have a friend whom I can trust him completely. （×） 公司一般会辞退（不能达成目标的）员工 Companies normally dismiss workers who （差了are）unable to achieve their goals.（×） Companies normally dismiss workers. They unable to achieve their goals.
要点3：关系代词指代先行词，在从句中作主语，从句谓语动词和先行词要主谓一致
我喜欢那个（有幽默感的）老师 I like the teacher. He has a sense of humor. I like the teacher who have（改成has） a sense of humor. The woman who live （改成lives）next door is a famous dancer. 阅读--填空题 Storms create____ns_____which absord whales' click.
要点4:区分关系代词和关系副词
关系副词指代先行词，在从句中充当状语（没有关系副词，从句自身是完整的） 这就是（我第一次遇见你的）那间图书馆 This is the library. In this library, I met you for the first time. This is the library where I met you for the first time. 关系代词指代先行词，在从句中充当宾语、主语（没有关系代词，从句自身是不完整的） 这就是（你喜欢的）那间图书馆 This is the library. You like this library. This is the library which you like. 这是一本（你能在里面找到很多有趣故事的）书 This is the book. In this book, you can find many interesting stories. This is the book where you can find many interesting stories. 这是（你找到的）那本书 This is the book which you found. 你要记住（你所选的）的日期 You should record the date which you choose.
要点5：非限定性定语从句
除了that之外，which/who/whom/whose/where/when都可以引导 用逗号与主句隔开 对先行词的补充说明，非限定限制
1）先行词是专有的（大写） I work for Tesla, which encourages all employees to make decisions.
2）先行词是唯一的 I love my mother, who teaches me a lot.
3）先行词已有很多限定，范围很小很具体的（共有的特性） This company is looking for employees who can work long hours. This company is looking for Asian male immigrants, who are normally willing to work long hours. 年轻人喜欢那些提供员工培训的公司 Young people like those companies（ ,去掉）which provide staff training. ? 年轻人一般喜欢大的跨国公司，这些公司通常提供员工培训 Young people like large transnational companies （加个，）which normally provide staff training. ? He has just come back from New York （加个，）which is a very big city in the United States. ?
4）非限定性定语从句可修饰一整句话 员工要学会和同时高效合作，这样能够提高生产力 Workers should learn to collaborate with colleagues efficiently, which can increase productivity.
要点6：介词+关系代词 引导的定语从句 which、whom
先行词在从句里面充当介词后的宾语，放在介词后面，介词可以提前放在关系代词前 （我们住的）房子很大 The house is very large. We live in this house. The house that/which we live in is very large.（√） The house in which we live is very large.（√） The house in that we live is very large.（×） 这就是那位（我跟她学英语的）老师 This is the teacher. I learn English from this teacher. This is the teacher whom I learned English from.（√） This is the teacher from whom I learned English.
要点7：关系代词的省略
关系代词指代先行词，在从句中充当宾语，关系代词可以省略 （我之前提到的）那个同事辞职了 The colleague has quitted his job. I mentioned the colleague. The colleague (whom) I mentioned has quitted his job. （在公共场所大声说话的）人应该被处罚 People （要加个who，在从句当主语）speak loudly in public places should be punished. ?
注意：先行词是the way，定语从句的关系代词往往会省略 我讨厌他处理这个问题的方式 I hate the way. In this way, he handled this problem. I hate the way （in which） he handled this problem.（√） I hate the way he handled this problem.（√）
要点8：as也可以引导定语从句，=which，指代先行词，在从句当中作宾语/主语
1）引导非限定定语从句,as指代主句,在从句当中作宾语/主语 Pollution has reached an alarming level, as(=which) we all know. 我们都知道/众所周知 Pollution has reached an alarming level. We all know this. The figure for China is the highest , as/which is shown in the chart. 如图所示 The figure for China is the highest , as/which we can see in the chart.如图所示
区别：as引导的非限定定语从句可放主句前后；which引导的非限定只能放主句后 As we all know, pollution has reached an alarming level.
2）引导定语从句：the same sth as... 他正在用一本（和我买的）一样的书 He is using the same book. I bought a book. He is using the same book as I bought.
注意：当主句和从句的动词一样时，用助动词do does did 代替从句的动词 我犯了一个（和他犯的）一样的错误 I made the same mistake as he made. I made the same mistake as he did. I made the same mistake as he.（×） 每天，我都吃（和他吃的）一样的水果 Every day, I eat the same fruits as he eats. Every day, I eat the same fruits as he does. Every day, I eat the same fruits as he.（×）
要点9：than也可以引导定语从句，=which，指代先行词，在从句当中作宾语/主语 先行词有比较级修饰，才会用than引导的定语从句修饰
青少年经受（比报道的）更少的压力 Adolescents experience less stress. Stress was reported. Adolescents experience less stress than（=which） was reported.（先行词在从句作主语） 我拥有（比我实际需要的）更多的钱 I have more money. I actually need money. I have more money than I actually need. （先行词在从句作宾语） 在广告的影响下，人们购买（比自己所需要的）更多的电子产品 Under the influence of advertisements, people buy more electronic devices. They need electronic devices. Under the influence of advertisements, people buy more electronic devices than they need.
状语从句
从句充当状语，修饰主句，由从属连词来连接主句和从句
从属连词
原因
because(因为) as(因为) since(既然) now that(既然) in that(因为) given that(鉴于，考虑到) considering that(鉴于，考虑到)
目的
so that(为了) in order that(为了) in case(免得，以防)
条件
if(如果) unless(除非) as long as(只要) provided that(如果) even if(即使) or(否则)
让步
although(虽然，尽管) though(虽然，尽管) while(虽然，尽管) even though(虽然，尽管)
时间
when(当...的时候) while(当...的时候) as(当...的时候) before(在...之前) after(在...之后) once(一旦) as soon as(一旦) since(自从...)
结果
so that(以至于) so(因此) so...that...(如此...以至于) such...that...(如此...以至于)
要点
要点1：从属连词引导状语从句，不能独立成句，必须连着主句 Although water is important. Few people consider it necessary to conserve it.（×） 并列连词引导的并列句可以独立成句 Water is important. But few people consider it necessary to conserve it.
要点2：状语从句放主句前，用逗号和主句隔开；状语从句放主句后可以不用 Although water is important, few people consider it necessary to conserve it. Few people consider it necessary to conserve water although it is important.
要点3：although 和but， because 和so不能连用，只需一个连词连接两个句子
要点4：since引导时间状语从句，从句用一般过去式，主句用现在完成时 I haven't played guitar since I left China.
要点5：while、as和when的区别
while、as后只能用延续性动词，不能用瞬间动词 when两种动词都可以用 当他的祖父去世时，他很难过 When his grandfather died, he was sad.
while也表示 “而” (用于从句之首，与主句内容相对比)=whereas Most digital camera owners are male, while women prefer film.
要点6：so that和so的区别
区别1：so that可引导目的状语从句“为了”，也可引导结果状语从句“因此，以至于” so指引导结果状语从句 “因此” I studied hard so that/so I got the scholarship. I should study hard so that I can get the scholarship.
区别2：so为并列连词，可独立成句，so that为从属名词，不能单独成句
要点7：so...that...和such...that的区别
so+形容词/副词+that such+名词+that The population is so big that the demand for water is massive. Water is used so fast that it cannot be replenished quickly. This country has such a big population that the demand for water is massive.
要点8：条件/时间状语从句和主句的时态配合 if（如果）/once（一旦）/as soon as（一旦）/when（当...）
一般情况：条件从句用一般现在时，主句用将来时（主将从现） +动词一般现在时，主句：主语+will+动词原形 I will buy a car when I will be rich.（×）
情况2：从句用一般现在时，主句用情态动词can, may, must, would+动词原形,表达不同情绪语气 If health care is free, the poor can have a better life. If students want to improve themselves, they must work hard.
情况3：如果描述的是一个客观的真理，一定会发生的事情，主句用一般现在时 If temperature drops to zero, water freezes.
要点9：区分易混淆的一些连词和介词 连词后可加句子，介词不可以（加名词、动名词）
连词
虽然，尽管
although，though,even though
因为，由于
because,since,as
当...的时候
while,when,as
由于，随着
as
As the demand for water increases, the government should charge higher fee.
介词
虽然，尽管
despite,in spite of
因为，由于
due to,because of
当...的时候
during,in
由于，随着
with
With the demand for water increasing,the government should charge higher fee.
即是连词也是介词
before, after, until, since既是连词（可接句子），也是介词（可接名词、动名词） After this policy is implemented, water can be used more efficiently. After the implementation of this policy, water can be used more efficiently.
要点10：区分易混淆的一些连词和副词 连词可连接两个句子，副词不可以
连词
但是 but
He is nice but I don't like him.
因此 so
He is nice so I like him.
副词
但是 however
He is nice. However, I don't like him.
因此 therefore/thus/hence
He is nice.Therefore I like him. He is nice and therefore I like him.
要点11：状语从句的省略（时间when、条件if、让步although状语从句）
情况1：从句和主句的主语一致 Tourists take photos when they visit cultural attractions. Tourists take photos when visiting cultural attractions.（1.从属连词+doing） Children may have behavioral problems if they are punished too often. Children may have behavioral problems if punished too often.（2.从属连词+done） This painting is popular although it is expensive. This painting is popular although expensive.（3.从属连词+形容词） Once the applicant was in the room, the applicant could not speak. Once in the room, the applicant could not speak.（4.从属连词+介词短语）
情况2：从句为it is/that is...结构 If it is necessary, you can come and ask me for help. If necessary, you can come and ask me for help.（从属连词+形容词） When it is possible, you should come and help. When possible, you should come and help.（从属连词+形容词）
子主题
句型
基本句型
主+谓+宾
I wear a hat. Students need help. Teaching requires patience. Children love playing games. She wants to quit her job. To study every day is difficult. I care for my grandfather. 主语：动作的发出者 宾语：动作的接受者 代词/名词/动名词/不定式 谓语：及物动词(vt) (transitive verb)、及物动词词组(vi+prep)
宾语：不定式(to do)? 动名词(doing)? 大部分取决于固定搭配 decide to do enjoy doing plan to do avoid doing fail to do allow doing
部分动词既可加不定式(to do)作宾语也可加不定式(to do)? 动名词(doing)，意思不一样 stop doing sth. stop to do sth. forget doing sth. forget to do sth.
不能充当主、宾：形容词/副词/介宾短语/分词
在国外有很多好处 In foreign countries has many advantages.(错，介宾短语不能做主语) Abroad has many advantages.（错，改成staying abroad 或者 being abroad） 我喜欢在家里 I like at home.（错，改成I like staying at home. 或者I like being at home.） 开心有益于健康 Happy benefits healthy.（错，改成Happiness benefits our health.）
主+系+表
This question is difficult. He is a teacher. Learning English is exciting. He is exhausted. My job is to teach French. Her home is in Shenzhen. Tom's French teacher is me. 表语：说明主语的特点（身份、性质、特征），修饰主语的 名词/代词/形容词/介宾短语/不定式/现在分词/过去分词
系动词：be(is am are was were been ) “是...” 联系主语和表语
持续：remain/keep/stay “依然是.... 保持是...” 变化：become/turn/grow/get “变成是.....” 表像：seem/appear/look “好像是... 似乎是...” 感官：taste/smell/sound/feel “吃起来是... 终止：prove/turn out “证明是...” “结果是....”
This problem becomes serious. I stayed at home yesterday. The figure remained unchanged. This toy looks interesting. Your answer seems wrong. It tastes good. This idea proves(to be)wrong
有些动词两种都可以 Stay Hungry 主系表 Stay Foolish 主系表 stay abroad（adv.）主谓结构
主+谓
I slept well last night. Many problems exist in this country. A meeting took place yesterday. 不及物动词(intransitive verb) 不及物动词词组：die out show up take place fade away 常常接状语
主+谓+间宾+直宾
I gave him a book. My boyfriend bought me a handbag. His parents prepare him a party every year. She asked me a question. 主+谓+间宾(sb.)+直宾(sth.) 双宾可换位,加to/for（固定搭配） 主+谓+直宾(sth.) to/for 间宾(sb.) I gave a book to him. My boyfriend bought a handbag for me. His parents prepare a party for him every year. offer sb sth? teach sb sth? choose sb sth?
主+谓+宾+宾补
I find this book useful. Delicious food made this journey interesting. Cheating made him punished. IELTS puts me under pressure. My teacher encourages me to make friends. Education can make students knowledgeable workers. 宾语补足语：补充说明修饰宾语，不能省，否则句子意思结构不完整 宾语是宾补的逻辑主语，之间有主谓关系、主系表关系 名词/形容词/介词短语/不定式/现在分词/过去分词
特殊句型
并列句
并列结构：由并列连词连接对等成分的单词、短语或句子 and ----- both A and B A和B or ----- either A or B 要么A要么B neither A nor B 既不是A也不是B but ----- not only A but also B 不仅A而且B so 所以，因此 由并列连词连接对等成分 Residents and animals have benefited from this project. 主语并列 This programme is successful and cost-effective. 表语并列 People hunted foxes and detroyed their habitats. 谓语+宾语并列 Students can study at home or at school. 状语并列 We should take action to protect wild species and to restore their habitats. 状语并列
要点1：并列连词连接的成分要对等 政府要么可以惩罚偷猎，要么可以在动物保护上花钱 The government can either punish poaching or it can(去掉) spend money on animal protection.
要点2：谓语动词并列，注意与同一个主语是否恰当配合 1）单复数的配合 栖息地的破坏已经变得很严重了，需要被解决 The destruction of habitats has become serious and needs（加s） to be tackled. 2）并列谓语是否能与主语搭配使用（语义） 栖息地的破坏已经变得很严重，需要保护 The destruction of habitats has become serious and （补主语：这些栖息地）should be protected.（意思不能跟主语搭配） 3）前否后肯，句子会有歧义 Animals cannot find food and die out. 改为前肯后否： Animals may die out due to the lack of food.
要点3：谓语动词并列，助动词、情态动词重复可省略 我已经洗完衣服、打扫完房间了 I have done the laundry and cleaned my room. 我不洗衣服也不打扫房间 I don't do the laundry or clean my room. 我必须洗衣服和打扫房间 I must do the laundry and clean my room.
要点4：主语并列，注意谓语的配合 1）and/both...and...连接主语，谓语用复数形式 Both his father and his wife speaks（改成speak） English. 2）or/either...or../neither...nor/but/not only...but also...连接主语，谓语和后面的主语配合：就近原则 Neither his father nor his children speak English. Neither his children nor his father speaks English. Either he or I am wrong. Not only they but also John has passed the exam.
要点5：并列连词and or but so可连接两个句子，也可单独引出一个句子 Eating animals is ethically wrong and/so it should be banned. Eating animals is ethically wrong. And/So it should be banned.
There be
there be句型相当于一个倒装句，表示“有”
注意1：there be的主语是be后面的名词，名词要和be保持一致 there are a large number of buildings.
注意2：there be 后面不能加独立的句子 有很多学生出国留学 There are many students study abroad. =有很多（出国学习的）学生 改为there be +名词+定语 There are many students who study abroad. There are many students studying abroad.
有大量的水被人们浪费=有大量的（被人们浪费的）水 There is a large amount of water is wasted by people.（×） There is a large amount of water which is wasted by people. There is a large amount of water wasted by people.
注意3：be可以有不同的时态：过去式 was/were; 现在完成时have been/has been; 将来时will be;情态动词+be 从2002年起，有两家图书馆已经开放给公众=有两家（已经开放给公众的）图书馆 Since 2002, there have been two libraries which have been open to the public. 一定有学生不喜欢这个决定=一定有（不喜欢这个决定的）学生 There must be some students who do not like this decision. There have three trees in the garden.（×）
强调句
句型：It is...that/who..... 强调人，用that/who都可以；但用who只能强调人 把要强调的部分（主语、宾语、状语）放在it is 后面，剩下的部分放到that/who后面 在传统课室里，老师可以一对一地帮助学生 In traditional classrooms, teachers can help students on a one-on-one basis. It is in traditional classrooms that teachers can help students on a one-on-one basis. It is teachers that can help students on a one-on-one basis. It is students that teachers can help on a one-on-one basis.
注意
注意1：is可以换成was，表达过去式；但不能变复数are/were I met my students at the railway station yesterday. 正是昨天，我在火车站碰到了我的学生们 It was yesterday that I met my students at the railway station 昨天我在火车站碰到的正是我的学生们 It was my students that I met at the railway station yesterday.
注意2：把it is...that/who去掉，句子要完整，主谓要一致 正是我,昨天在火车站碰到我的学生们 It was me （改成I）that met my students at the railway station yesterday.（×） Me met my students at the railway station yesterday. 对孩子有巨大影响的正是学校教育（schooling） It is schooling that have(改成has) a huge impact on children.（×） Schooling have a huge impact on children.
区分强调句和主语从句 强调句只能强调： 主语（名词/动名词）、宾语（名词/动名词）、状语（介宾短语/状语从句）
主语从句/强调句
It's+名词+that
主语从句:that后面引导的从句，肯定是完整的 It is a pity that you cannot eat shrimps.
It is reported that 16 people were killed in the earthquake.（主语从句） It is a pleasure that I get this car.（主语从句）
强调句：that后面引导的句子不完整，缺主语或宾语 It is shrimps that you cannot eat. You cannot eat shrimps.
It is after 10 a.m. that he does sports every day.（强调） It is Tom that likes questioning others. （强调）
主语从句
It's+形容词+that
It's clear that
It's+分词+that
It's reported that
强调句
It's+介词短语+that
It's at school that I meet him.
It's+状语从句+that
It's when I am at school that I meet him.
倒装句
only+状语放句首，句子要倒装（系动词、助动词、情态动词提前）
主系表：只有和他在一起，我才开心 I am happy only with him. Only with him,am I happy.
主谓宾，只有和他一起，我才学雅思 I study IELTS only with him. Only with him, do I study IELTS. 只有和我一起，他才学雅思 He study IELTS only with me. Only with me, does he study IELTS. 上一年，只有和我一起，他才学雅思 He study IELTS only with me last year. Only with me, did he study IELTS.
only+状语放句首，句子要倒装（系动词、助动词、情态动词提前） 谓语由情态动词+动词原形组成：只有和他一起，你才能解决这个问题 You can solve this problem only with him. Only with him, can you solve this problem.
注意：only+主语，句子不倒装 只有你可以解决这个问题 Only you can solve this problem.
not only...but also...连接两个句子，not only放在句首，not only引导的前半句要倒装（系动词、助动词、情态动词提前）,also 放到后半句的谓语动词前/系动词后
他不仅是我们的队长，也是我们的好朋友 主系表：He is not only our team leader, but also our close friend. Not only is he our team leader, but he is also our close friend.
过度工作不仅导致压力，而且降低效率. 主谓宾：Overwork not only causes stress but also reduces efficiency. Not only does overwork cause stress but it also reduces efficiency.
注意：not only...but also...连接两个主语，句子不倒装 Not only my colleagues but also I am friendly.
否定词放句首，句子需要倒装（系动词、助动词、情态动词提前） never, hardly, seldom, rarely,barely
他几乎不迟到 He is barely late. Barely is he late. 我从未写过2000字的作文 I have never written a 2000-word essay. Never have I written a 2000-word essay. 上一年，他很少学英语 He seldom studied English last year. Seldom did he studied (换成study)English last year.（×） 他很少学英语的 He seldom studies English. Seldom does he studies (换成study)English.（×）
so 形容词/副词 that+结果状语从句，若so.....放句首，主句倒装（系动词、助动词、情态动词提前）
他的书如此有趣，以至于很多老师都推荐 His book is so interesting that it has been recommended by many teachers. So interesting is his book that it has been recommended by many teachers. 他学习如此用功，以至于很多老师表扬他 He studied so hard that many teachers praised him. So hard did he study that many teachers praised him.
such+名词 that+结果状语从句，若such.....放句首，主句倒装（系动词、助动词、情态动词提前）
他是一个如此友好的人，以至于他有很多朋友 He is such a nice boy that he has many friends. Such a nice boy is he that he has many friends.
not until+状语从句 放句首，主句倒装
直到他赢了这次比赛，他才变得出名 He did not become famous until he won this match. 时间状语从句 Not until he won this match did he become famous.
方位介词放句首，句子完全倒装（地图题）
村庄位于路旁边 The village was next to the road. Next to the road was the village. 大农场位于南部 A huge farm lies in the south. In the south lies a huge farm.
虚拟语气
如果我得到了100亿，我就不学雅思了 真实条件句（主将从现） I will not study IELTS, if I get 10 billion dollars. 主将（ 一般将来时） 从现（一般现在时） 虚拟条件句（不可能发生的） 对现在的虚拟（现在不可能） I would not study IELTS, if I got 10 billion dollars. 主句（would/should/could/might+动词原形） 从句（一般过去式） 对过去的虚拟（过去不可能） 之前如果我好好学语法，我就考过雅思了 I would have passed the IELTS, 主句（would/should/could/might+have done) if I had studied English grammar hard. 从句（had+done 过去完成时） 如果我之前没有拒绝你的话，我们可能已经结婚了 We could have got married, if I hadn't refused you.