请问ball games算是单数还是复数?

问题描述:

请问ball games算是单数还是复数?
比如说 我说我喜欢球类运动.
My favourite sports are ball games.
是这样写的么?

双数比如说 我说我喜欢球类运动。My favourite sports are ball games.是这样写的么?不是 应该是My favourite sport are ball games