Robert's garden tap is dripping. Pip came to fix it, and every plan he names starts with a little helper — can, must, should.
No to after the modal
A modal sits in front of a bare verb. No to.
I can fix this tap.
You must shut the water.
She should call them.
I can to fix this tap.
No -s, no didn't can
The modal does not take -s. And it does not take did.
He can fix it.
He cans fix it.
I could not stop it.
I didn't can stop it.