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。