1. 不定式
1) 形式
主动形式 被动形式
一般式 to do to be done
完成式 to have done to have been done
进行式 to be doing
完成进行式 to have been doing
a) 完成式: 不定式的一般形式所表示的动作, 通常与主要谓语表示的动作(状态)同时(或几乎同时)发生, 或是在它之后发生. 假如不定式所表示的动作, 在谓语所表示的动作(状态)之前发生, 就要用不定式的完成式.
I am glad to have seen your mother (= I am glad I have seen your mother).
(比较: I am glad to see you.)
He is said to have written a new book about workers.
He pretended not to have seen me.
b) 进行式: 如果主要谓语表示的动作(状态)发生时, 不定式表示的动作正在进行, 这时要用不定式的进行式.
You are not supposed to be working. You haven’t quite recovered yet.
We didn’t expect you to be waiting for us here.
He pretended to be listening attentively.
c) 完成进行式: 在谓语所表示的时间之前一直进行的动作, 就要用不定式的完成进行式.
The struggle was known to have been going for twenty years.
We are happy to have been working with you.
d) 被动式: 当不定式的逻辑上的主语是不定式所表示的动作的承受者时, 不定式一般要用被动形式.
It is an honour for me to be asked to speak here.
She hated to be flattered.
He wanted the letter to be typed at once.
This is bound to be found out.
There are a lot of things to be done.
She was too young to be assigned such work.
2) 功用: 不定式可以作主语 (a), 宾语 (b), 表语 (c), 定语 (d) 或是状语 (e).
a. To scold her would not be just.
b. We are planning to build a reservoir here.
c. One of our main tasks now is to mechanize agriculture.
d. Do you have anything to declare?
e. We have come to learn from you.