Present perfect and past (1) (I have done and I did)

A. Study this example situation:

 

     Tom is looking for his key. He can't find it.

 

     He has lost his key. (present perfect)

     This means that he doesn't have his key now.

     Ten minutes later:

     Now Tom has found his key. He has it now.

     Has he lost his key? (present perfect)

  

     No, he hasn't. He has found it.

     Did he lose his key? (past simple)

     Yes, he did.

     He lost his key (past simple)

     but now he has found it. (present perfect)

    The present perfect is a present tense. It always tells us something about now. 

    'Tom has lost his key' = he doesn't have his key now (see Unit 7).

    The past simple tells us only about the past. If somebody says 'Tom lost his key',

    we don't know 

    whether he has it now or not. We only know that he lost it at some time in the

    past.

    Two more examples:

    * Jack grew a beard but now he has shaved it off. (so he doesn't have a beard

       now)

    * They went out after lunch and they've just come back. (so they are back now)

B. Do not use the present perfect if there is no connection with the present (for
     example, things that happened a long time ago):

 

    * The Chinese invented printing. (not 'have invented')

   * How many plays did Shakespeare write? (not 'has Shakespeare written')

   * Beethoven was a great composer. (not 'has been')

 Compare:

   * Shakespeare wrote many plays.

   * My sister is a writer. She has written many books. (she still writes books)

C. We use the present perfect to give new information (see Unit 7). But if

     we continue to talk about it, we normally use the past simple:

   * A: Ow! I've burnt myself.

      B: How did you do that? (not 'have you done')

      A: I picked up a hot dish. (not 'have picked')

  * A: Look! Somebody has spilt milk on the carpet.

     B: Well, it wasn't me. I didn't do it. (not 'hasn't been ... haven't done')

     A: I wonder who it was then. (not 'who it has been')

EXERCISES

13.1 What has happened in these situations?

      1. Jack had a beard. Now he hasn't got a beard. He has shaved off his beard.

      2. Linda was here five minutes ago. Mow she's in bed. She ---

      3. The temperature was 25 degrees. Now it is only 17. The temperature ---

      4. The light was off. Now it is on. Somebody ---

      5. The tree was only three metres high. Now it is four. The tree ---

      6. The plane was on the runway a few minutes ago. Now it is in the air.

 The plane ---

13.2 Put the verbs in brackets in the correct form, present perfect or past simple.

       1. 'Where's your key?' 'I don't know. I've lost it.' (lose)

       2. I was very tired, so I lay down on the bed and went to sleep. (be)

       3. Mary --- to Australia for a while but she's back again now. (go)

       4. 'Where's Ken?' 'He --- out. He'll be back in about an hour.' (go)

       5. I did German at school but I --- most of it. (forget)

       6. I meant to phone Diane last night but I --- (forget)

  

       7. I --- a headache earlier but I feel fine now. (have)

      8. Look! There's an ambulance over there. There --- an accident. (be)

      9. They're still building the new road. They --- it. (not/finish)

    10. 'Is Helen still here?' 'No, she --- out.' (just/go)

  

    11. The police --- three people but later they let them go. (arrest)

   12. Ann --- me her address but I'm afraid I --- it. (give, lose)

   13. Where's my bike? It --- outside the house. It --- (be, disappear)

   14. What do you think of my English? Do you think I ---? (improve)

13.3 Are the underlined parts of these sentences right or wrong? Correct the ones

         that are wrong.

     1. Do you know about Sue? _She's given up_ her job. RIGHT

     2. The Chinese _have invented_ printing. WRONG: The Chinese invented

     3. How many plays _has Shakespeare written?_ ---

     4. _Have you read_ any of Shakespeare's plays? ---

     5. Aristotle _has been_ a Greek philosopher. ---

     6. Ow! _I've cut_ my finger. It's bleeding. ---

     7. My grandparents _have got_ married in London. ---

     8. Where _have you been born?_ ---

     9. Mary isn't at home. _She's gone shopping._ ---

   10. Albert Einstein has been the scientist who _has developed_ the theory of

          relativity. ---

13.4 (Section C) Put the verb into the most suitable form, present perfect or past

          simple.

     1. A: Look! Somebody has split (spill) coffee on the carpet.

         B: Well, it wasn't (not/be) me. I didn't do (not/do) it.

 

    2. A: Ben --- (break) his leg.

        B: Really? How --- (that/happen)?

        A: He --- (fall) off a ladder.

   3. A: Your hair looks nice. --- (you/have) a haircut?

       B: Yes.

       A: Who --- (cut) it? --- (you/go) to the hairdresser?

       B: No, a friend of mine --- (do) it for me.