as的幾種用法：1.做連詞，固定搭配as……as，意思是“和……壹樣”；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……壹樣”
例句：
My sister is as tall as me.
我姐姐和我壹樣高。
He runs as fast as me/I.?
他和我跑得壹樣快。
She is as beautiful as me/I.?
她和我壹樣漂亮。
Being a mother isn't as bad as I thought at first!
做壹位母親並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。