1) 动词+ 不定式
afford　 aim appearagree　 arrangeask　be　 decide　bothercarechoose come　 dare demand　desiredetermine expect　electendeavor　hope　fail　 happen　 helphesitate　learn　 long　mean manage　 offer　 ought planprepare　pretend promise　refuse　seem tend wait　 wish undertake
举例：　
　The driver failed to see the other car in time.
司机没能及时看见另一辆车。
　I happen to know the answer to your question.
我碰巧知道你那道问题的答案。

2）动词+不定式 ；　动词+宾语+不定式
ask, beg, choose, expect , hate, help intend like, love, need prefer, prepare, promise, want, wish…
　I like to keep everything tidy.　我喜欢每件东西都保持整洁。
　I like you to keep everything tidy.　我喜欢你年使每件东西都保持整洁。
I want to speak to Tom.　 我想和汤姆谈话。
I want you to speak to Tom.　 我想让你和汤姆谈话。

3） 动词+疑问词+ to
decide, know, consider forget, learn, remember, show, understand, see, wonder, hear, find out, explain, tell
Please show us how to do that. 请演示给我们如何去做。
There are so many kinds of tape-recorders on sale that I can't make up my mind which to buy.有这么多的录音机，我都拿不定主意买哪一种。

注意:疑问词带不定式在句中作成分时，谓语动词用单数。
The question is how to put it into practice.
问题是怎样把它付诸实施。