1)as, (just)as…so…引導(dǎo)的方式狀語從句通常位于主句后，但在(just)as…so…結(jié)構(gòu)中位于句首，這時(shí)as從句帶有比喻的含義，意思是"正如…"，"就像"，多用于正式文體，例如：

　　Always do to the others as you would be done by.

　　你希望人家怎樣待你，你就要怎樣待人。

　　As water is to fish, so air is to man.

　　我們離不開空氣，猶如魚兒離不開水。

　　Just as we sweep our rooms, so we should sweep backward ideas from our minds.

　　正如打掃房屋一樣，我們也要掃除我們頭腦中落后的東西。

　　2)as if, as though

　　兩者的意義和用法相同，引出的狀語從句謂語多用虛擬語氣，表示與事實(shí)相反，有時(shí)也用陳述語氣，表示所說情況是事實(shí)或?qū)崿F(xiàn)的可能性較大。漢譯常作"仿佛……似的"，"好像……似的"，例如：

　　They completely ignore these facts as if (as though)they never existed.

　　他們完全忽略了這些事實(shí)，就仿佛它不存在似的。(與事實(shí)相反，謂語用虛擬語氣。)He looks as if (as though)he had been hit by lighting.

　　他那樣子就像被雷擊了似的。(與事實(shí)相反，謂語用虛擬語氣。)It looks as if the weather may pick up very soon.

　　看來天氣很快就會(huì)好起來。(實(shí)現(xiàn)的可能性較大，謂語用陳述語氣。)說明：as if / as though也可以引導(dǎo)一個(gè)分詞短語、不定式短語或無動(dòng)詞短語，例如：

　　He stared at me as if seeing me for first time.

　　他目不轉(zhuǎn)睛地看著我，就像次看見我似的。

　　He cleared his throat as if to say something.

　　他清了清嗓子，像要說什么似的。

　　The waves dashed on the rocks as if in anger.