complain about complain for complain at complain的区别

complain about complain for complain at complain的区别
complain about complain for complain at complain的区别

complain about complain for complain at complain的区别
complain about后面多跟sth,即complain about sth 指抱怨什么事；
complain for多侧重因什么而抱怨；
complain at 多跟sb,即complain at sb,指抱怨某人.