as的幾種用法：1.做連詞，固定搭配as……as，意思是“和……一樣”;2.做連詞，表示“當……的時候”;3.做連詞，表示“因為”4.做連詞，表示“盡管”等。

　　1.as做連詞，固定搭配as……as，意思是“和……一樣”

　　例句：

　　My sister is as tall as me.

　　我姐姐和我一樣高。

　　He runs as fast as me/I.

　　他和我跑得一樣快。

　　She is as beautiful as me/I.

　　她和我一樣漂亮。

　　Being a mother isn't as bad as I thought at first!

　　做一位母親并不像我當初想的那樣糟!

　　2.as做連詞，引導時間狀語從句，意思是“當……的時候”

　　例句：

　　My mother was cooking fish as I arrived home.

　　當我到家的時候，我媽媽正在做魚。

　　I was always hard up as a student.

　　我當學生時總是很拮據。

　　The crowd cheered as she went up the steps to the bandstand.

　　當她走上演奏臺的臺階時，人群歡呼起來。

　　All the jury's eyes were on him as he continued.

　　所有陪審員的目光在他繼續下去時都集中在了他身上。

　　3.as做連詞，引導原因狀語從句，意思是“因為”

　　例句：

　　As rain has fallen, the air is cooler.

　　因為下過雨，所以空氣比較涼爽。

　　Enjoy the first hour of the day. This is important as it sets the mood for the rest of the day.

　　享受一天中的第一個小時。這很重要，因為這第一個小時決定當天其余時間的情緒。

　　4.as做連詞，引導讓步狀語從句，意思是“雖然，盡管”

　　例句：

　　Young as he is, he has been one of the most famous painters in our country.

　　雖然他還很年輕，但已經成為我們國家最有名的畫家之一。

　　Happy as they were, there was something missing.

　　盡管他們很快樂，但總缺少點什么。

　　Much as they hope to go home tomorrow, they're resigned to staying on until the end of the year.

　　盡管他們很希望明天就回家，但不得不待到年底。

　　5.as做關系代詞，引導定語從句

　　例句：

　　This is the same game as I played yesterday.

　　這和我昨天玩的游戲一樣。

　　As Albert Einstein suggested, things should be as simple as possible, but no simpler.

　　正如愛因斯坦認為的那樣，事情要盡可能地簡單，而不是簡單一些。

　　6.as做介詞，意思是“作為”

　　例句：

　　French is known as the most beautiful language in the world.

　　法語以世界上最美麗的語言著稱。

　　Personas are represented as individual people.

　　作為個體代表的人物角色。

　　He has worked as a diplomat in the U.S., Sudan and Saudi Arabia.

　　他曾做過駐美國、蘇丹和沙特阿拉伯的外交官。

　　The news apparently came as a complete surprise.

　　這消息顯然是個徹頭徹尾的意外。

　　I really value him as a friend.

　　我真的把他視為好朋友。