He is always complaining to me about his fate.为什么要加is?

问题描述:

He is always complaining to me about his fate.为什么要加is?

be always doing 表达说话人的某种态度.
可以是赞赏、厌恶、憎恨等.
如:He is always helping others.
My deskmate is always asking me for something.