When communicating in Chinese you may often make mistakes using Chinese grammar like:

False:

    你家有什么口人？

    Nǐ jiā yǒu shénme kǒu rén

True:

    你家有什么人？

    Nǐ jiā yǒu shénme rén?

“什么”作修饰成分时，与中心语（“人”）之间不能用量词。删去“口”。

No measure word is allowed between 什么 as modifier and its head word（人）. Delete 口.