basketball
He is terrible at basketball.
maths
He isn't very good at maths.
run
He isn't very good at running. He is bad at running.
cook
He is very good at cooking. He is good at cooking.
run
They are good at running./They are quite good at running.
swim
She is good at swimming./She is quite good at swimming
maths
He is very good at maths.
cook
They are bad at cooking. / They are terrible at cooking.
swim
He is bad at swimming.
basketball
He is good at basketball.
windsurf
She is good at windsurfing.
take photos
He is good at taking photos.
arts
They are very good at arts.
arts
She isn't very good at arts.
windsurfing
She isn't very good at windsurfing