用於兩者之間的同級比較，表示"…和…一樣"：
① "as +原級形容詞+as"的`結構，表示前後兩者的情況一樣
"A+系動詞+as+形容詞原級+as+ B，
eg. Bill is as funny as his father.
My handwriting is as beautiful as yours. 我的書法和你的一樣好。
"A+謂語動詞+as+副詞原級+as+ B"
eg. Lucy speaks Chinese as well as Lily.
② 在否定句中，用"not as/ so +原級形容詞as"結構，表示前者不如後者。
"A+系動詞+not as/so+形容詞原級+as十B"
eg. These books aren't as interesting as those.
I am not as/ so busy as I used to be. 我沒有過去那麼忙了。
"A+助動詞/情態動詞+not+謂語動詞+as/so+ B"
eg. She didn't sing so well that night as she usually does.
③ 如若第一個as/ so後的形容詞作定語修飾名詞，應將該名詞及有關修飾語都放在第一個as/ so之後。
We have produced as many tractors as we did last year. 我們生產的拖拉機和去年一樣多。
I don't make as/ so much money as you do. 我掙得錢不如你掙得多。
