They usually watch TV after supper.But this time they are listening to the radio.为什么watch不加es
问题描述：
They usually watch TV after supper.But this time they are listening to the radio.为什么watch不加es
答
这个是标准的英语语法，只有行为动词在第三人称单数的情况下才要加“s”或者“es”,而本句是标准的第三人称复数。
答
因为主语是they（复数） 谓语动词用复数
答
因为主语是they～
es只用在第三人称单数的场合～
看：
He usually watches TV after supper.But this time he is listening to the radio.
只有主语是he/she/it等第三人称单数,才用es/s的啦~