衛(wèi)生類職稱英語考試語法：非謂語動詞�？嫉钠渌�結(jié)構(gòu)

（1）疑問詞+不定式結(jié)構(gòu)

疑問詞who，what，which，when，where和how后加不定式可構(gòu)成一種特殊的不定式短語。它在句中可以用作主語、賓語、表語和雙重賓語。

When to start has not been decided.何時動身尚未決定。（主語）

I don't know what to do.我不知道該怎么辦。（賓語）

The difficulty was how to cross the river.困難在于如何過河。（表語）

I can tell you where to get this book.我可以告訴你哪里可以買到此書。（雙重賓語）

（2）不帶to的不定式

1）在表示生理感覺的動詞后的不定式不帶to.

這類詞有： feel 覺得 observe 注意到，看到 overhear聽到 watch注視 listen to聽 perceive察覺，感知 notice注意 see看見 look at看 hear聽

On seeing the young child fell into the lake,Eric sprang to his feet，and went on the rescue.

2）另一類是某些使役動詞，如make，let，have等。

Let him do it.讓他做吧。

I would have you know that I am ill.我想讓你知道我病了。

①上述感覺動詞與使役動詞轉(zhuǎn)換為被動結(jié)構(gòu)時。其后的不定式一般需帶to，

He was seen to come. The boy was made to go to bed early.

3）在do nothing/anything/everything but（except）結(jié)構(gòu)中。

例如：Last night I did nothing but watch TV.昨天晚上，我除了看電視別的什么也沒有干。

但是，如果謂語動詞不是“do nothing，anything，everything”，那么but（except）所跟的不定式則仍須帶。

The doctor told him nothing but to stop smoking.醫(yī)生除了讓他戒煙，其它什么都沒有說。

There was nothing for them to do but to remain silent.除了保持沉默以外，他們沒有別的辦法。