He has a great sports collection collection为什么不加S sports为什么加S

sports 是 adj.运动的 适于运动的
sport 是 n.运动 I think swimming is an exciting sport.
还是vt.(及物动词) 炫耀夸饰 sport one's wealth
还有vi.（不及物动词）游戏玩耍 they are sporting in the playground.
所以这里用sports 而不是sport
collection（1）收集,采集,收取时 可以视为[C]也可以是[U]
eg.The collection of the photos takes me two months.
(2)收藏品,收集的东西[C]
eg.He has a very good collection of Chairman Mao's medals.这里指的是他收藏的东西的总称,而不是一个两个三个奖章,所以用作单数.这个例子中的collection和你问题中的collection的用法是一样的.他有个很不错的体育方面的收藏.首先 a great 不表示大量的不同于 a great deal of 和a great many 其次collection是指收藏,而不是一件两件三件的收藏品.
如果一定要加s的话,可改为 he has a great deal of sports collections.
I hope you will be satisfied with my words.