Present Perfect Tense

We use the present perfect to say that an action happened at an unspecified time before now. The exact time is not important. You can't use the present perfect with specific time expressions, such as :

- yesterday
- one year ago
- last week
- when I was a child
- when I lived in Japan
- at that moment
- that day
- one day

We can use the present perfect with unspecific expressions, such as: ever, never, once, many times, several times, before, so far, already, yet.

• Rumus

1. Bentuk Verbal

          [+] S + Have/has + V3 + Adj
          [-] S + Have/has + not + V3 + Adj
          [?] Have/has + S + V3 + Adj

     2. Bentuk Nominal

          [+] S + Have/has + been + Adj
          [-] S + Have/has + not + been + Adj
          [?] Have/has + S + been + Adj

• Example

          ~ Verbal : 
             1. I think I have met him once before
             2. People have not traveled to Mars
             3. Have you read the book yet?
             4. We have eaten or lunch already
             5. I have not made an animation 3D for along time

             6. They have had three tests in the last week

             7. We have not visited him

             8. Rina has not finished his homework yet
             9. Has she heard the news?
            10. The concert has already started

         ~ Nominal :
            1. I have gained five pounds since I started my diet
            2. She has been in the Universal Studio since yesterday
            3. That castle has been visited by many tourists
            4. Has she been sick for two days?
            5. They have not been busy for one day
            6. He has not been here for 20 minutes.
            7. Has he been here for 20 minutes?
            8. He has not eaten meat since 1997
            9. She has been here since yesterday
           10. They had been at book store since morning