You really took care not to have your father know.

His mother and father would know what he had done, however.

If his father had known, he kept the knowledge to himself.

And if I know, you can be sure your father knows.

I don't think my father knew he was actually a man.

His father took one look at him and knew exactly what had happened.

Her father did not know what to do with George.

Your father knew when those books were found what you needed.

The father knows he's really dead but never seems to give John a chance.

My father, because he kept the books, knew exactly what was going on.