情态动词之后( used to , have to, ought to除外);would rather…than ;prefer to do rather than do ;had better do; would rather do ;can’t help but do等。
当like 或want在由when,whenever,what,whatever,as,if等引导的状语从句中时,其后往往省略整个动词不定式。如;
You can do whatever you like.
You can do nothing if you don’t want.
省略动词不定式,只保留符号to的场合:
(1)当动词不定式在hate,intend,would like,need,hope,plan,wish,try,expect,refuse,advise等动词后作宾语时。如:
-----Do you want to go home now ?
-----Yes, I want to.
在某些形容词后作状语时。如:
Would you like to go home now ?
Yes, I’d be glad to.
(3)当承前省略的不定式是be或作助动词的have 时,to后要保留be或have。
如:Do you want to be a tether in the near future ?
Yes ,I want to be .
五.动词不定式的特殊结构
1. 特殊疑问词+动词不定式相当于名词,在句中可作主语、宾语、表语、定语.如:
I don’t know what to do next.(宾语)
The problem is how to help him.(表语)
When to start hasn’t been decided .(主语)
2. 动词不定式的复合结构:就是在不定式前加上其逻辑主语,其形式为:It + be +adj. + for\of +动词不定式。在这种结构中,用for 还是of 取决于前面的形容词,当形容词时描述不定式动作时用for;当它是描述不定式的逻辑主语,说明其品质、特征或属性时要用of,常用的形容词有nice,good,clever,wise,foolish,honest,kind,careful,brave,stupid等。
总之,要全面而科学的学好和掌握好动词不定式,在高考中获胜,就得在平时的教学和学习过程中全面的复习,而不是仅教或学一点皮毛而已。