1.不定式做主語
(1)做形式主語的代詞：
不定式做主語, 通常用it充當(dāng)形式主語, 把做主語的不定式短語后置。 如：
It took me only five minutes to gydjdsj.org.cn finish the job.
To be frank, it is a great relief to have the task fulfilled in so short a time.
(2)引導(dǎo)邏輯主語的介詞：
不定式的邏輯主語一般由介詞for引導(dǎo),但下列表示人的性格行為特征的形容詞做表語時, 不定式的邏輯主語則由of引導(dǎo)：
absurd, bold, brave, courageous, careful, careless, clever, wise, foolish, silly, stupid, good, nice, kind, thoughtful, considerate, greedy, generous, honest, modest, polite, rude, cruel, selfish, lazy, wicked, wrong。如：
Experts say walking is one of the best ways for a person to stay healthy.
It’s clever of you to have invented such a device.
(3)不定式做主語補足語：
掌握常用不定式做主語補足語的句型。注意不定式表示的動作發(fā)生的時間，并采用相應(yīng)形式。如：
said
reported
thought
be to do sth.
believed
known
supposed
Byron is said to have lived gydjdsj.org.cn on vinegar and potatoes.
The bank is reported in the local newspaper to have been robbed in broad daylight yesterday.
