Is their mother tall?这句话用Is 还是用are?

问题描述:

Is their mother tall?这句话用Is 还是用are?

用is.1.因为这句话的陈述句应该为 Their mother is tall.
2.their mother 没有用复数,是单数第三人称.
所以变为一般疑问句式仍应该用is.