/as + adjective +as/

我們使用/as + adjective + as /來表達相等的概念

Cats are as friendly as dogs.

我們使用/are not as +adjective +as / 結構來表達不相等的概念。

Turtles aren't as expensive as parrots.

你可以在/as/前加一個副詞。這用於強調或提供更多的資訊。

Cats are just as friendly as dogs.
Cats are never as friendly as dogs.
Cats are sometimes as friendly as dogs.

Other adverbs is ok.