find、think等词后面跟不定式时,常用 it 作形式宾语,而将真正的宾语(即不定式)后置。After the operation you may find it difficult to chew and swallow.
定语
起形容词的作用
something/ anything/ nothing等+(形容词)+不定式
不定式也可以是“不定式+介词”结构,这里的介词一般不可省去。
I want some paper to write on.我想要一些写字的纸
不定式所修饰的名词是 time、place 或 way 时,不定式后面习惯上要省略介词。
The library is a good place to study.图书馆是一个学习的好地方。
表语
表示主语的具体内容、目的等,可以跟主语进行位置互换 My dream is to be/ become a famous scientist.= To be/ become a famous scientist is my dream.
作宾语补足语
主语+动词+宾语+to do allow 允许; order命令; teach 教; ask 要求; want想要; invite 邀请; encourage 鼓 励; tell告诉; warn 警告; advise 建议; expect期望; wish 想要; force 强迫; decide 决定; would like 想要
状语
目的状语
表示“为了做”;常用的短语有: to do、 in order to do、 so as to do,
作结果状语
多指出乎意料的结果,only to do 不料,竟然
常用的结构
① so/ such... as to do sth.如此……以至于做某事;
② … enough to do sth.足够……能够做某事;
③ too… to do sth.太……而不能做某事;
作原因状语
be glad/ sad/ happy/ sorry/ pleased/surprised/ disappointed/ delighted/ shocked to do sth.。
评注性状语
作独立成分,to be honest 老实说; to begin/ start with 首先; to tell (you) the truth 说实话To be honest, it is one of the worst books I' ve ever read.
动词不定式的常用结构和句型
“疑问词+不定式(短语)”结构
too… to do …太...而不能.......
… enough to do…足够....做某事...
it be+ adj.+ for/ of sb.+ to do sth.
it's one's turn to do sth.轮到某人做某事
it takes/ took sb.+时间+ to do sth.某人花多长时间做某事。
it's time to do sth./ it's time for sth.是该做某事的时候了。
to 的省略
使役动词和感官动词后省略 to 的情况let、 make、 have 等使役动词和 feel、 see、 watch、 notice、 look at、listen to、hear
why (not) do…
help (sb)do sth
but、 except之前有实义动词 do 的任何形式(do、 does、did、done),其后通常省略动词不定式符号 to,否则要带 to。 His mother could do nothing but wait for the doctor to arrive. I have no choice but to accept the fact.