Past Simple Tense (I did = S+V2)
1. Study this example:
        Wolfgang Amadeus Mozart was an Austrian musician and composer. He lived from 1756 to 1791. He started composing at the age of five and wrote more than 600 pieces of music. He was only 35 years old when he died.
Lived / started / wrote / was / died are all past simple.
2. Very often the past simple ends in  -ed (regular verb)
        - I work in a travel agency now. Before that I worked in a shop.
        - We invited them to our party but they decided not to come.
        - The police stopped me on my way house last night.
        - She passed her examination because she studied work hard.
** But many verbs are irregular. The past simple does not end in -ed. For example:
        Write              wrote          - Mozart wrote more than 600 pieces of music
        See                saw             - We saw Jenny in town a few days ago.
        Go                 went            - I went to the cinema three times last week.
        Shut               shut             - It was cold, so I shut the window.       
3. In  question and negatives we use did / didn't + infinitive (enjoy / see / go) :
        - Did you go out last night?  Yes, I went to the cinema but I didn't enjoy the film
        - When did Mr. Thomas die?  About ten years ago.
        - Did you have time to write the letter?  No, I didn't.
        - I didn't do anything.