He was an English teacher last year.（肯定句)
He wasn't an English teacher last year.（否定句）
Was he an English teacher last year?（一般疑问句）
Yes,he was./No,he wasn't.
1去年划线:When was he an English teacher?
2他划线:Who was an English teacher last year?
3是一个老师划线 What was he last year?