Modals – 'can' and 'can't'

We can use can and can't to talk about abilities in the present.

I can swim.
They can speak English.
He can't ride a bike.

How to use them

Use the infinitive without to after can and can't.

I can swim.
You can run fast.
She can ride a bike.
We can't speak Japanese.
They can't play the guitar.

For questions, change the order of can and the person.

Can you swim? Yes, I can.
Can she play the piano? No, she can't.
What languages can you speak?