depart for 和set off的区别

depart for后面一定要接目的地, set off 则不用.
The flight is scheduled to depart for Beijing at eight thirty.
We are scheduled to set off at eight thirty.

depart for
离开去...
We departed for London at 10 am.
我们上午10点动身去伦敦.
Mr. Smith departed for New York.
史密斯先生出发去纽约了。
set off
出发
What time are you planning to set off tomorrow?
你打算明天几点钟启程?
They've set off on a journey round the world.
他们已经开始环游世界.

depart for 及物性短语 后接宾语
set off 不及物短语 不接宾语

depart for 指离开现在的地方去某地。
例如：I depart for Beijing now. 我现在就出发去北京。

set off仅指出发。
I will set off at 5 o'clock. 我将5点出发。