represent 同on behalf of 有什麼分別?

on behalf of somebody/ on somebody's behalf，詞性：preposition phrase。

解釋有三：

1.as the representative of somebody or instead of them，代表/ 代替某人。
Mr Chan cannot be here, so his wife will accept the prize on his behalf.

2.US寫法：in behalf of somebody/ in somebody's behalf；
in order to help somebody，為了幫忙某人。
We collected money in behalf of the homeless.

3.because of somebody; for somebody，因為某人。
Don't worry on my behalf.

represent，詞性：verb。　由於represent是verb，所以跟on behalf of somebody的用法不同，但意思與上面的解釋一有點相似。
意思是to speak, act or be present officially for another person or people，代表某人。

柯林斯字典有這樣的解釋：
If someone such as a lawyer or a politician represents a person or group of people, they act on behalf of that person or group.

If you represent a person or group at an official event, you go there on their behalf.

If you represent your country or town in a competition or sports event, you take part in it on behalf of the country or town where you live.

例句：
They chose a famous barrister to represent them in court.
The general secretary may represent the president at official ceremonies.
My only aim is to represent Britain at the Olympics.

總結：
represent是動詞；但on somebody's behalf是preposition phrase，所以用它時要加上動詞。

2010-08-25 10:32:41 補充：
例子：
He represented her.
He did sth on her behalf.