What most parents are concerned about is.语法请问为什么这句话中要加个are,不能说What most parents concerned about is.如果换care about ,前头要不要加个are?

问题描述:

What most parents are concerned about is.语法
请问为什么这句话中要加个are,不能说What most parents concerned about is.
如果换care about ,前头要不要加个are?

be concerned about这是固定词组
care about不用加be动词
而What most parents are concerned about 是本句句子的主语