1.除了構(gòu)成謂語外(如與情態(tài)動詞構(gòu)成復合謂語),不定式還可在句中用作:
1)主語:
To go or not to go is a question.
去還是不去是一個問題。
It is not easy to learn English well.
學好英語是不容易的。
2)賓語:
He decided to give up the job.
他決定放棄這項工作。
Tell me how to do it.
告訴我該怎樣做。
3)表語:
My job is to look after the baby.
我的工作是照顧寶寶。
4)定語:
I have a lot of things to do.
我有很多事情要做。
5)狀語:
He often comes to see us.
他常來看我們。
不定式還可構(gòu)成復合賓語(即作賓語的補語):
She told me not to go out.
她讓我別出去。
2.不定式有時不帶to:
I saw a man enter the room.
我看見一個人進屋來了。
3.有時還有被動(a)完成(b)及進行形式(C):
a. She like to be praised.
她喜歡受人贊揚。
I was glad to have been invited.
受到邀請我很高興。
b. I'm sorry to have given you so much trouble.
對不起給你添了這么多麻煩。
c. She seemed to be talking with somebody.
她似乎在和人談話。