在肯定句主语是第三人称单数时中所有动词是不是都要变单三,不管有多少个都要变?

首先,前提条件是一般现在时,其次是没有情态动词时,另外还有此动词是做谓语时.比如：1、He wanted to play football last Sunday.But his father did not agree.2.She can play the piano.3.Lucy needs to go to scho...