找错误并改正:My friend Tim is good at swim.

问题描述:

找错误并改正:My friend Tim is good at swim.

swim改为swimming
be good at doing 擅长做...固定用法
因为其中at为介词,所以后面接动词要名词化
可以理解为
在.方面不错
在游泳方面不错
所以swim游泳方面,应该采用名词形式的swimming