Надо составить 2 предложение с was и 2 предложение с время was - ед.ч were- мн.ч)

А какие именно? ну если was/were использовать в качестве модального глагола то,например :i was played piano yesterday. they were watched TV two days ago

Nick was at that time. The little girl was afraid of the dog. You were glad to hear this news. Her parents were at the theatre last nigth.