You not
You aren't good at running.
They
They are good at driving.
He not
He isn't good at flying.
You
You are good at skiing.
It not
It isn't good at writing.
We not
We aren't good at swimming.
She
She is good at skating.
It
It is good at cooking.
We not
We aren't good at dancing.
She not
She isn't good at singing.