too…to 結構通常表示否定意義:

She was too young to understand all that.

enough…to結構則表示肯定意義:

She was not old enough to understand all that.

not too, but too, all too, only too等和不定式連用時,不定式一般不表示否定意義:

He's only too pleased to help her.

so…as (to)這種結構也可用不定式作狀語:

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

如果要說明不定式表示的動作是誰做的, 可以在不定式前加一個for引起的短語:

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.

在以某些形容詞(如 kind, good, nice, wise, unwise, clever, silly, wrong, right, foolish, stupid, careless, considerate, rude, naughty, impolite等)作表語時, 不定式前可加一個of引起的短語, 來說明不定式指的是誰的情況:

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.

V+ing形式(現在分詞及動名詞)

形式

完成式: 如果要表示動名詞代表的動作在謂語所表示的動作之前發生, 通常用動名詞的完成形式.

He didn't mention having met me.

I regret not having taken her advice.

在某些動詞后(或成語中), 常用(或可以用)動名詞的一般形式, 盡管動作是在謂語所表示的動作之前發生的.

Excuse me for coming late.

I don't remember ever seeing him anywhere.

現在分詞的完成式主要用在狀語中, 表示這動作在謂語所表示的動作之前發生.

Having been there many times, he offered to be our guide.

Having found the cause, they were able to propose a remedy.

另外, 獨立結構也可用現在分詞的完成形式.

The guests having left, they resumed their discussion.

The children, having eating their fill, were allowed to leave the table.

被動式: 當一個動名詞邏輯上的主語所表示的是這動作的對象時, 動名詞一般要用被動形式.

His being neglected by the host added to his uneasiness.

He couldn't bear being made fun of like that.

但要注意, 在want, need, deserve, require 等動詞后, 盡管表示的是被動的意思, 卻用動名詞的主動形式.

My pen needs filling.

The point deserves mentioning.

This problem requires studying with great care.

在worth這個形容詞后情形也是這樣.

Her method is worth trying.