be good at加名詞,介詞賓格或名詞性短語,很重要的就是如接動詞要加動詞的ing形式.
如I am good at teaching English.I am good at football.
be good at后面要接名詞、動名詞或名詞/動名詞短語，
例句：John is good at swimming and basketball.
It is important that we try to be good at everything we do.
I have a shrill voice. I'll never be good at singing.
I am good at chess, but not checkers.