a. Study this example :
§ I enjoyed the party very much.
§ Mr. Brown died ten years ago.
§ When I lived in Athens, I worked in a bank.
b. Very often the simple past ends in –ed:
§ We invited them to our party, but they decided not to come.
§ The police stopped me on my way home last night.
§ She passed her exam because she studied very hard.
But many important verbs are irregular. This means that the simple past doesn’t end in –ed:
Leave ––» left We all left the party at 11:00.
Go ––» went Last month I went to Rome to see my friend.
Cost ––» cost This house cost $75,000 in 1980.
The past of the verb be (am/is/are) is was/were:
c. In simple past questions and negatives we use did/didn’t + the base form (do/open, etc.) :
§ Ann : Did you go out last night, Tom?
Tom ; Yes, I went to the movies. But I didn’t enjoy it.
§ When did Mrs. Johnson die?
§ What did you do over the weekend?
§ We didn’t invite her to the party, so she didn’t come.
Note that we normally use did/didn’t with have:
§ Did you have time to write the letter?
§ I didn’t have enough money to buy anything to eat.
But we don’t use did with the verb be (was/were):
§ Why were you so angry?
§ Was Mark at work yesterday?
§ They weren’t able to come because they were very busy.
Sumber : Murphi, Raymond. 1989. Grammar In Use. Australia: Cambridge University