1）在否定句或疑問句中可用so… as。
He cannot run so/as fast as you.

2）當as… as 中間有名詞時采用以下格式。
as +形容詞+ a +單數名詞
as + many/much +名詞
This is as good an example as the other is.
I can carry as much paper as you can..

3）用表示倍數的詞或其他程度副詞做修飾語時，放在as的前面。
This room is twice as big as that one.
Your room is the same size as mine.　　

4) 倍數+ as + adj. + as　<=> 倍數+ then + of.
This bridge is three times as long as that one.
This bridge is three times the length of that one.
Your room is twice as large as mine.
Your room is twice the size of mine.