Question

Когда в past simple использовать was,were,а когда did?

Answer 1

В страдательном залоге - was, were (Was this text translated at the last lesson?)
В действительном залоге - did  (Did he live in London?)

Answer 2

was, were как is, are.
а did как do, does
Примеры: He was (is) doctor. They were (are) teachers.
Did (does) he say anything? Did (do) you go there?