he enjoys playing basketball

比如 he seldom ... 就不用加“s”啊。。 那么到底还有什么要加&quot....为什么要加“s”

enjoy是动词，跟在He这个第三人称单数后面要加s
但是seldom是个频率副词，就不用加的

a enjoy常用作及物动词,意思是“喜欢” 、“乐于” 、“享受……的乐趣” . 现将其用法简述如下： 一、 enjoy后接名词或代词. 【例如】： they are enjoying their dinner. 他们在津津有味地吃饭. do you enjoy the film? 你喜欢这部电影吗? alice doesn't enjoy it. 爱丽斯不喜欢它. 二、 enjoy后面可接动词的-ing形式. 【例如】： i enjoy listening to light music. 我喜欢听轻音乐. do you enjoy reading? 你喜欢读书吗? he doesn't enjoy singing. 他不喜欢唱歌. many students enjoy asking questions in english. 许多学生喜欢用英语问问题. 三、 enjoy后面可接反身代词(oneself),构成固定搭配enjoy oneself,意为“过得愉快、玩得高兴” ,相当于have a good time. 【例如】： — did you enjoy yourself at the party? 你在聚会时玩得高兴吗? — i enjoyed myself very much at the party. 我在聚会时玩得真开心. 1.enjoy后接动词时必须接动词的 -ing形式,不能接动词原形或动词不定式（to do）. 【例如】： 他喜欢踢足球. [误] he enjoys play football. [误] he enjoys to play football. [正] he enjoys playing football. 2.enjoy后只能接表示褒义的词组. 【例如】： 他母亲身体不健康. [误] his mother enjoys very poor health. [正] his mother doesn't enjoy good health.