that's what you are good at这里为什么要加what?类似的还有you are what you wear.

问题描述:

that's what you are good at这里为什么要加what?类似的还有you are what you wear.
还有,YOU 的Be动词到底是什么,为什么有时候是is有时候是are?例如is you?和you are a girl.

what 作为 good at 的宾语