Keep quiet bare infinitive
To keep silent.
The teacher said, "Keep silent, John."
Please keep silent when I am talking.
To prevent someone from revealing the information.
She was bribed to keep silent about the personal information of a rapist.
The murder intimidated the witness into keeping silent.
Used to tell someone to keep secret what you're about to say
Very quiet
To be secretly working together
Kept in secret
The verb "keep" should be conjugated according to its tense.