1) 动词 不定式
    afford   aim     appear    agree   arrange    ask      be       decide  bother    care    choose     come       dare     demand  desire    determine         expect      elect    endeavor          hope              fail   happen   help    hesitate  learn   long      mean     manage   offer   ought     plan    prepare  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。