1. 基本用法

該結構的基本意思是“與……一樣”，其中接形容詞或副詞的原級，在否定句中，第一個 as 也可換成 so。如：

He doesn’t study as [so] hard as his brother. 他學習不如他弟弟努力。

2. 涉及數量或程度的用法

若涉及數量或程度，可用“as much+不可數名詞+as”和“as many+可數名詞復數+as”。如：

He doesn’t pay as much tax as we do / as us. 他沒我們交的稅款多。

There are not as many restaurants as there were. 現在餐館沒有過去多了。

3. 有關詞序的一點說明

其間接形容詞時，有時該形容詞還可修飾另一名詞，但這個名詞應帶有不定冠詞(注意詞序)。如：

I have as good a voice as you. 我的聲音和你一樣好。

4. 該結構的修飾語

根據情況可用(not) nearly, almost, just, nothing like, exactly, not quite, half, one-ten, twice, three times, 30 per cent等修飾，并且這些修飾語必須置于第一個as之前，而不能置于其后。如：

This room is twice as large as that one. 這個房間是那個房間的兩個大。

You’re not half as clever us you think you are. 你遠不是自己想像的那么聰明。

It took three times as long as I had expected. 這件事比我預料的多花了兩倍的時間。