英语语法 名词性从句

高中英语语法名词性从句的思维导图，本导图有助于帮助您熟悉知识要点，加强记忆。有需要的同学，可以收藏下哟

名词性从句

• 主语从句、表语从句、宾语从句、同位语从句,在整个句子中所起的作用,相当于一个名词，因此,这四种从句通称为名词性从句 引导名词性从句的连接词可分为三类: 连接词: that, whether, if(不充当从句的任何成分) 连接代词: what, whatever, who, whoever, whom, whose,which. 连接副词: when, where, how, why
• 主语从句
  • 作句子主语的从句叫主语从句，主语从句通常由 从属连词 that ,whether, if 连接代词 what, who, which ,whatever,whoever 连接副词how, when, where, why 等词引导, that 在句中无词义，只起连接作用;连接代词和连接副词在句中既保留自己的疑问含义、又起连接作用，在从句中充当从句的成分
    • What he wants to tell us is not clear.他要跟我们说什么,还不清楚 lt is known to us how he became a writer.我们都知道他是如何成为一名作家的 where the English evening will be held has not vet been announced.英语晚会将在哪里举行,还没有宣布
  • 有时为避免句子头重脚轻,常用形式主语it代替主语从句作形式主语放于句首,而把主语从句置于句末，主语从句后的谓语动词一般用单数形式 (1) lt+be+名词+that从句 (2)lt+be+形容词+that 从句 (3)lt+be+动词的过去分词+that 从句 (4).lt+不及物动词+that 从句 另注意在主语从句中用来表示惊奇、不相信、惋惜、理应如此等语气时,谓语动词要用虚拟语气“(should)+do". It is necessary (important, natural, strange,etc.) that … It is a pity (a shame.no wonder, etc.) that…. lt is suggested (requested, propose d, desired, etc.) that.
• 宾语从句
  • 由连接词that,引导的宾语从句 由连接词that 引导宾语从句时, that在句中不担任任何成分，在口语或非正式的文体中常被省去，但如果从句是并列句时,第二个分句前的that不可省
    • He has told me that he will go to Shanghai tomorrow.他已经告诉我他明天要去上海 We must never think (that) we are good in everything while othersare good in nothing. 我们决不能认为自己什么都好.别人什么都不好
  • 在 demand, order,suggest,decide, insist, desire, demand,request, command等表示要求、命令、建议、决定等意义的动词后,宾语从句常用(should)+动词原形”
    • I insist that she (should) do her work alone.我坚持要她自己工作 The commander ordered that troops (should) set off at once.司令员命令部队马上出发
  • 用who, whom, which. whose, what, when, where, why,how, whoever, whatever, whichever等关联词引导的宾语从句相当于特殊疑问句,应注意句子语序要用陈述语序
    • l want to know what he has told you.我想知道他告诉了你什么 She always thinks of how she can work well.她总是在想怎样能把工作做好 She will give whoever needs help a warm support.凡需要帮助的人,她都会给予热情的支持
  • 用whether 或 if引导的宾语从句，其主语和谓语的顺序也不能颠倒,仍保持陈述句语序此外, whether与if在作“是否"的意思讲时在下列情况下一般只能用whether,不用if A.引导主语从句并在句首时; B.引导表语从句时; C.引导从句作介词宾语时;D.从句后有“or not"时; E.后接动词不定式时
    • Whether there is life on the moon is an interesting question.月球上有没有生命是个有趣的问题 Everything depends on whether we have enough money.一切要看我们是否有足够的钱
• 表语从句
  • 在句中作表语的从句叫表语从句，引导表语从句的关联词与引导主语从句的关联词大致一样，表语从句位于连系动词后,有时用as if引导 主语+系动词+that 从句
    • The fact is that we have lost the game.事实是我们已经输了这场比赛 That is why he didn't come to the meeting.那就是他为什么不到会的原因 lt looks as if it is going to rain.看上去天要下雨了
  • 当主语是 reason时,表语从句要用that引导而不是because
    • The reason why he was late was that he missed the train by oneminute this-morning 他迟到的原因是因为他今早晚了一分钟错过了火车
• 同位语从句
  • 同位语从句用来对其前面的抽象名词进行解释说明,被解释说明的词和同位语在逻辑上是主表关系,通常使用that引导同位语从句,that只在句首或句中起连接作用，不做任何成分
  • 同位语从句的先行词通常为answer, hope, fact, truth, belief,news, idea, promise, information,conclusion, order, suggestion,problem, question, thought, report, belief, decision, doubt, opinion,theory等抽象名词
    • The news that his heath is failing made us sad.他健康状况不佳的消息使我们很难过。 l have no idea where they are spending their holidays.我不知道他们在哪里度假。 The question who should do the work requires consideration.谁该干这项工作的问题需要考虑。