The past continuous tense

USE:

We use the past progressive to say what was (not) happening around (before, at and perhaps after) a past time.

STRUCTURE

Affirmative: (pro)noun + was, were + verb with -ing (we always add -ing at the end of the verbs in this tense)

I saw my English teacher while I was going to school.

Negative:  (pro)noun + was, were + not + verb with -ing 

He wasn't wearing his glasses.

Interrogative:  was, were + (pro)noun + verb with -ing 

Was  he going to school?

Short answers:

Yes, he was. Or, No he wasn't.