注意

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

2. 不定式作补语

1) 动词+宾语+不定式(to do)

advise, allow, appoint, believe, cause, challenge, command, compel, consider, declare, drive, enable, encourage, find, forbid, force, guess, hire, imagine, impel, induce, inform, instruct, invite, judge, know, like, order, permit, persuade, remind, report, request, require, select, send, state, suppose, tell, think, train, trust, understand, urge, warn

a. Father will not allow us to play on the street.　父亲不让我们在街上玩耍。

b. We believe him to be guilty. 我们相信他是有罪的。

Find 的特殊用法

Find 后可用分词做宾补，或先加形式宾语，再加形容词，最后加带to 的动词不定式。find后也可带一个从句。此类动词还有get，have。

I found him lying on the ground.

I found it important to learn.

I found that to learn English is important.