to add sth on or to add on sth
1.+ cost, service另外加上；额外加上
Many loan application forms automatically add on insurance.很多贷款申请表会自动附加保险。
2.+ room, wing扩建；加盖
To the rear is a large dining room, added on early this century.后部是一个本世纪初加盖的大餐厅。
A new bathroom has been added on to the back of the house.房子后面加盖了一个新浴室。