We are all against his idea. 我们都反对他的想法。
He was married against his will. 他结婚是有违本意的。
He spoke against the new law. 他发言抨击新法律。
There were 20 votes for him and 12 against him. 有20票赞成他，12票反对他。
He stood with his back against the door. 他背靠门站着。
He hit his head against the window. 他的头撞到了窗户上。
It is difficult to see anything against this bright light. 对着这种强光很难看到任何东西。
Bright red flags flow in the wind against the blue sky. 鲜艳的红旗映着蓝天迎风飘扬。
2. 注意 against 是介词，不是动词。如：
正：He leaned against the tree.
误：He against the tree.
正：Are you for or against the plan?
误：Do you support or against the plan?
正：I’m against doing anything till the police arrive.
误：I’m against to do anything till the police arrive.