as if 與as though用法概述

as if 與as though是一組同義詞，意思相同，用法也相同，但多數(shù)情況下人們喜歡用as if，因?yàn)槠浜喍獭?/p>

1. 通常情況下，as if/as though所引導(dǎo)從句的謂語動詞為虛擬語氣，表示所述情況與事實(shí)相反。
Why is she looking at me as though she knew me?
她為什么那樣看著我，好像認(rèn)識我似的？

2. 如果as if后面的從句表示的情況是真實(shí)的或者很可能是真實(shí)的，則動詞可以用陳述語氣。

He walks as if he is drunk.
He walks as if he were drunk.
第一句表示“他已經(jīng)醉了”，第二句則表示“他沒有醉”。

3. 在非正式文體中，可以用like代替as if/as though
It looks like it's going to rain today.

4. 當(dāng)asif/as though引導(dǎo)的從句主語和主句的主語一致時，該主語和后面的動詞可以省略，于是出現(xiàn)了以下幾種情況。
1) as if+不定式
He opened his lips as if (he were)to make some reply.
2) 不定式+adj.
She felt unable to endure such a life.
她覺得似乎無法再忍受這種生活了。
3) as if+介詞短語
He looked about as if (he was)
in search of something.
4) as if+現(xiàn)在分詞
John paused as if expecting Mary to speak.
5) as if+n.
He acts as if (he was) a fool.

puncture n./v. 刺穿
Our tires do not puncture easily.
我們的輪胎不易爆破。
I've got a puncture and my spare is flat too!
我的車胎扎破了，備用的也癟了！

scratch v. 抓，撓，刮擦
The dog is scratching at the door.
狗正在抓門。

run v. 運(yùn)營，經(jīng)營
He has no idea of how to run a business.
他不知如何經(jīng)商。