Past simple negative and question

When we create a past simple sentence with an action verb, we use 'did'. The negative of that is "did not" which shortens to "didn't".

e.g.

I did not go to the shops yesterday - I didn't go to the shops yesterday.

"didn't" goes after the subject and before the main verb.

When we use a form of "be" in past simple we make it was/were. So when it is negative, it is "wasn't" or "weren't"

e.g.

We weren't there yesterday.

In these sentences, we make the verb "be" negative and we don't add "did".

When creating a question, we transform the sentence in the past in the same was as in the present.

e.g.

He liked his new computer. - Did he like his new computer?

We put "did" at the start of the question, unless we are using a question word. And because we have used "did" to make it the past, the main verb is used in V1.

What did you like?

If we are making a question with a sentence that has a form of "be" as the main verb, then we do not use "did".

e.g.

This was my place - Was this your place?

The main verb moves to the front of the sentence in front of the subject.