1 . be behind with [in ] 拖欠，拖延，不能如期完成。如：

He is never behind with [in] his work. 他工作從不拖拉。

He was behind in [with] his rent. 他拖欠了房租。

He helped a classmate who was behind with his homework. 他幫助一位沒有按時完成作業(yè)的同班同學。

2 . be behind in doing sth 做某事不落在后面。如：

The boy is behind in handing in homework. 這孩子沒能按時交家庭作業(yè)。

He was never behind in offering suggestions. 他提建議從來不落在別人后面。

3 . from behind 從后面。如：

He held her from behind. 他從后面抱住她。

They attacked us from behind. 他們從后面攻擊我們。

注：有時 behind 是介詞，其后可接賓語。如：

He came out from behind the door. 他從門后出來。

4 . fall [drop ] behind 落在后面。如：

I’ve fallen behind in work. 我工作落后了。

Some students dropped behind in their studies. 有的學生在學習上落在后面。

5 . leave sth behind 走后留下某物。如：

What have we left behind? 我們走后留下什么了？

He left his umbrella behind. 他離開時沒有把雨傘帶走。

6 . stay [remain ] behind 留下，在別人后面留下。如：

He alone remained behind. 只有他一個人留下沒走。

I had to stay behind after school. 放學后我還得留在學校。