The verb To Be hasn't got a negative form.
_______ she at work yesterday?
My grandparents _______ driving home.
I _______ going with you.
The Verb To be has 3 forms in the Present Tense.
The Past form of the Verb To be is only WAS.
The Past Participle of the Verb To be is BEEN.
I _______ as tall as you.
Emily _______ studying yesterday.
Tom and Peter _______ friends.