The verbs was and were are also forms of the verb be.
Was is the simple past tense of am and is. Use was with
the pronouns I, he, she and it, and with singular nouns.
Beethoven was a German composer.
Sue was at the library this morning.
It was very wet on Monday.
Ten years ago she was only a baby.
He was not well yesterday.
Last year she wasn’t tall enough to reach the high shelf.
Samantha was second in the race, wasn’t she?
Were is the simple past tense of are. Use were with the
pronouns you, we and they, and with plural nouns.
The Romans were brave soldiers.
They were third in the wheelbarrow race.
There weren’t any clouds in the sky.
Were you still in bed when I phoned?
We were on the same school team.
Those were my best jeans.
Kaynak: Basic English Grammer Book1