①动词不定式的基本形式是“to+动词原形”,有时可以不带to。动词不定式没有人称和数的变化,在句中不能单独作谓语。
②动词不定式具有名词、形容词和副词的特征,因此可以在句中作主语、表语、宾语、宾语补足语、定语和状语。
③用作主语的动词不定式常用it作形式主义,把动词不定式放在后面。
如:It’s polite to use a large spoon and a fork to eat in Thailand.
④动词want, hope, like, begin, try, need, forget, learn, plan, decide等后面常接不定式作宾语。
如:I like to ride a bicycle to the park.
⑤动词ask, tell, want, invite, wish, allow, teach等后面常接不定式作宾语补足语。
如:They invite me to go to Paris with them.
⑥make, have, let等使役动词及see, watch, notice, feel, hear等感官动词后面常接不带to的不定式作宾语补足语。
如:She always tells me jokes and makes me laugh.
⑦动词不定式的否定形式由“not+动词不定式”构成
动词不定式可以和疑问词what, how, which, where, when等连用
如:I don’t know what to do.