How many children (does) your uncle( have)?为什么要用does和 have?

问题描述:

How many children (does) your uncle( have)?为什么要用does和 have?

主语是“ your uncle”,第三人称单数,助动词用第三人称单数“does”,而助动词"do / does /did"后面的行为动词都必须用原形,所以后面的动词用have,不能用has