Is your mother and you fine?为什么不用are?为什么要用is?

Is your mother and you fine?为什么不用are?为什么要用is? 为什么here is your book and your coat的谓语动词用is不用are? how is your study going为什么用is不用are? jenny and i are quiet 为什么用 are 不用 is Where are you from为什么用are不用is ARE YOU FROM london 为什么用ARE不用IS where（does）your mother works?为什么不用is How is ( are ) your mother 为什么 是 is what is your mother hobby?为什么不用Does而是用Is? 为什么用who is it 而不用who are you? how are lucy and tony.这句话为什么要用are而不用 is? 英语中what is your name?中is为什么不用are而用is