as if 用法歸納：
as if一般可由as though來(lái)代替。可在look, seem等系動(dòng)詞后引導(dǎo)表語(yǔ)從句。如:
It seems as if it is going to rain.
看來(lái)好像要下雨了。
as if 從句的語(yǔ)氣及時(shí)態(tài)
當(dāng)說(shuō)話者認(rèn)為句子所述的是真實(shí)的或極有可能發(fā)生或存在的事實(shí)時(shí),as if從句用陳述語(yǔ)氣。如:
It sounds as if it is raining.
聽(tīng)起來(lái)像在下雨。