Rules.
1 In affirmative sentences, we use was or _____.
2 In negative sentences, we use _____ or weren't.
3 In yes / no questions, we use ____ / were + pronoun + the verb in the base form.
4 In short answers, we use yes / no + pronoun + _____ / wasn't or were / weren't.

In affirmative sentences, we use was or were_.
2 In negative sentences, we use wasn't_ or weren't.
3 In yes / no questions, we use was_ / were + pronoun + the verb in the base form.
4 In short answers, we use yes / no + pronoun + was/ wasn't or were / weren't.