depart : 较正式用词，指经过周密考虑或郑重地离开，强调离开的起点。
- Flights for Rome depart from Terminal 3.
- She waited until the last of the guests had departed.
- The train departed Amritsar at 6.15 p.m.
leave : 侧重出发地而不是目的地。
- I'll be leaving at five o'clock tomorrow.
- He left the house by the back door.
- She left the group of people she was with and came over to speak to us.
- The bus leaves in five minutes.
go : 一般用词，指从所在地到其它地方去，着重目的地而非出发地。
- Is it midnight already? I really must go/must be going.
- She wasn't feeling well, so she went home early.
- What time does the last train to Bath go?
- I'm afraid he'll have to go (= be dismissed from his job) - he's far too inefficient to continue working for us.
- This carpet's terribly old and worn out - it really will have to go (= be got rid of).
start : 可与leave换用，强调目的地，但不及leave普通。
- What time are we starting tomorrow?
quit : 侧重指离开令人烦恼的地方，或摆脱使人不快的人或事。
- We decided it was time to quit the city.
- The landlord gave them all notice to quit .
- Police were called when he refused to quit the building.
set out : 书面用词。
- When setting out on a long walk, always wear suitable boots.
- The troops are about to set out.
- They set out in a westerly direction along the riverbank.
- He got up at four and set out on foot to hunt black grouse.
- Four of the most powerful men in Russia set out on a top-secret mission.