詞性不同、具體含義不同、用法不同。seat意為“使就坐”、“使坐下”、“能坐下(容納下)”等，是及物動詞。sit表示“坐”、“就坐”，通常是不及物動詞。sit的過去分詞是sat，但用作表語、定語、賓語補足語等時，卻通常要用seated。

sit的例句

The students sit in a circle on the floor.

學生們圍坐在地板上。

Come and sit here beside me.

過來坐在我旁邊。

Can I sit next to you?

我能坐在你旁邊嗎？

He took off his coat and sat down.

他脫下外套坐下。

seat的例句

She seated herself at her desk.

她在桌子旁坐下。

He seated himself behind the desk.

他坐在桌子后面。

He seated himself on the sofa.

他坐在了沙發(fā)上。

John was seated on my left.

約翰坐在我的左邊。