书上的一句话:
What musical instruments can you play?
I can play the drums.
为什么用复数呢?
1. musical instrument 意思是“乐器”,是可数名词,可以用单数或复数:
What musical instrument can you play? 你会演奏哪种乐器?
What musical instruments can you play? 你会演奏哪些乐器?
2. play the drums 也可以说成 play the drum,参见:
https://www.cpsenglish.com/question/63268