SIMPLE PAST NEGATIVE

Even in cases of regular verbs, the formation of the "past simple" negation is simpler than the affirmation, since its structure is reduced to the following expression:
[Subject] + did + not + [Verb in infinitive (without "to")].

For the verb to be, you don’t need the auxiliary did. When the subject of the sentence is singular, use was not or wasn’t. When the subject is plural, use were not or weren’t.