解释一下动词不定式

动词不定式除了谓语不能做，其他成分都可以。如：我想学好英语。I want to learn English well.
to learn 就是动词不定式做宾语。我有很多作业要做。I have a lot of homework to do. to do 就是动词不定式做定语。To say is easy, to do is hard.
to say, to do 就是动词不定式做主语。My job is to clean the street. to clean 就是动词不定式做表语。

7.1 不定式作宾语

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 kee