he is good at
He is good at arithmetic.
He's good at rugby.
Ouvi dizer que ele é bom em mahjong.
I heard he's good at mahjong.
He's good at card games.
O Tom diz que ele é bom em malabarismo.
Tom says he is good at juggling.
He is good at diving.
He's good at biology.
O Tom diz que ele é bom em natação.
Tom says that he is good at swimming.
Ele é bom em resolver problemas complicados de matemática.
He is good at solving complicated math problems.
He is good at physics.