Past Tense

Today we are going to be past tene:

You use past tense when you want to express actions that you did and what already finish.

Principal auuxiliary in past tense is "DID" You must did with all pronouns.

you shouldn't use the auxilyary "DID" in affirmative sentences just in negative sentences.

when you use "DID" in a sentence the verb back to usual form it can't change.

Example:

Affirmative:

You worked in a factory until yesterday.

Negative:

You Didn't work in a factory until yesterday.

Question:

in the question the auxiliary verb change of place with the pronoun.

Example:

Did you work in a factory until yesterday?

Short answers:

Yes, I Did

No, I Didn't..

In this link you can practice past tense :

http://www.english-room.com/pasttense_6a.htm