Refuse, Reject, Deny: What’s the Difference?

You can refuse a noun or a verb.
He refused the job.
They refused to hire him.

You can only reject a noun.
I rejected their job offer.
They rejected his application.

Deny is usually about saying something isn’t true.
I denied breaking the window.
(They said I did it; I’m saying I didn’t do it.)

We deny a noun or gerund. 

He denied the accusations.

Deny is also about not letting someone have something.
He applied for the job, but his application was denied (passive).
They denied his application (active).