Réponse :
Michael Jackson was a famous singer. He wasn't British, he was American.
The Beatles were a famous English group. They were from Liverpool.
Princess Diana was Prince Charles's wife. She was beautiful.
Was/Were you at school yesterday ? No I/we was/were at home.
Explications :
Was est utilisé pour parler d'UNE SEULE PERSONNE.
Were est utilisé pour parler de PLUSIEURS PERSONNES.
Cela est la même chose pour les formes négatives.