1. Were the children at home yesterday morning?
2. No, they weren't . They were at the zoo.
3. I was at the zoo with my mum.
4. These flowers are beautiful. Were they expensive?
5. Sam was at school yesterday.
Объяснение:
Were, was - это глагол "быть" ("be") в прошедшей форме.
Weren't, wasn't - это тоже самое только в отрицательной форме
He, She, It, I - was, wasn't
They - were, were not