Foreigners often make some strange mistakes in Chinese when they study the most difficult language--- ---Chinese. We try to analyze typical sentences to correct these errors.
Nǐ jiā yǒu shénme kǒu rén?
False: 你家有什么口人？
Nǐ jiā yǒu shénme rén?
True: 你家有什么人？
“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）. delet 口.
