大学英语四级语法精要：不定式的其他用法

不定式的其他用法

too…to 结构通常表示否定意义:

she was too young to understand all that.

enough…to结构则表示肯定意义:

she was not old enough to understand all that.

not too, but too, all too, only too等和不定式连用时,不定式一般不表示否定意义:

he’s only too pleased to help her.

so…as (to)这种结构也可用不定式作状语:

be so kind as to drop in some time when you are free.

如果要说明不定是表示的动作是谁做的, 可以在不定式前加一个for引起的短语:

it is not hard for one to do a bit of good.
it is a great honour for us to be present at this rally.

在以某些形容词(如 kind, good, nice, wise, unwise, clever, silly, wrong, right, foolish, stupid, careless, considerate, rude, naughty, impolite等)作表语时, 不定式前可加一个of引起的短语, 来说明不定式指的是谁的情况:

it’s kind of you to think so much of us.
(it is) awfully good of you to come and meet us.
it’s very nice of you to be so considerate.
it’s unwise of them to turn down the proposal.