El pasado simple del verbo «To be» (ser o estar) se forma cambiando las formas «am» e «is» por «was» y la forma «are» por «were».
Por lo demás, para formar la negativa y la interrogativa la forma es la misma que en el presente simple.

Pronombre	Forma Afirmativa	Forma Negativa	Forma Interrogativa
I	was	was not / wasn’t	Was I ?
You	were	were not/ weren’t	Were you ?
He	was	was not / wasn’t	Was he ?
She	She was	was not / wasn’t	Was she ?
It	was	was not / wasn’t	Was it ?
We	were	were not/weren’t	Were we ?
They	were	were not/weren’t	Were they ?