1.although连接的让步状语从句,后面主句中不能再用连接词but.
2.although和though 同义,
3.在短语even though（即使）和as though（仿佛,似乎）中不能换用 although.
4.倒装句使用though,不嫩管用although.
如：young though he is,he knows a lot
5.though 可以做副词,‘但是’,放在句尾,although不能.
如：English is difficult,interesting ,though.