Once you understand how to form the past tense of regular verbs, you shouldn't find it difficult to use verbs in the present-perfect. All you'll need to add is an auxiliary verb (also known as a helping verb)--has or have.
Coupled with the auxiliary verb has or have, a past participle can serve as the main verb in a sentence. Compare these two sentences:
- Carla worked here for five years.
- Carla has worked here for five years.
We use has or have with a past participle to describe an action that started in the past and is (or may be) still going on. This construction is called the present-perfect.
The past participle form of a regular verb is identical to the past form: it always ends in -ed:
- Olga has promised to help me.
- Max and Olga have finished the race.
- We have tried to do our best.
- Carla has worked here for five years.
- Carla and Fred have worked here for five years.
EXERCISE: Forming the Past Tense and the Present-Perfect
Complete the second sentence in each set with the correct form of the verb in parentheses. Use either the past tense or the present-perfect tense (has or have plus the past participle). The first sentence in each pair will help you decide which tense is needed in the second sentence. When you're done, compare your responses with the answers on page two.
- Mr. Baggins lives in the house next door. He (live) there for the past eight years.
- We are still raising money for the scholarship drive. So far we (raise) over $2,000.
- I have gained five pounds since I started my diet. At the same time, I (gain) a craving for Milky Way bars.
- I watched the Jon Stewart show last night. Then I (watch) David Letterman's program.
- I have called you several times this week. You (call) me once last spring.
- Jenny frequently uses the new word processor. Kyle not (use*) it once.
- Several years ago I stayed two weeks on a farm. I (stay) in the city ever since.
- Addie shouted in my ear. I turned and (shout) right back.
- Lu ordered one book from the club last year. He not (order*) anything since.
- I have never tried to raise chickens. Once I (try) to raise hogs.
* The negatives not and never often go between the auxiliary verb and the past participle in the present-perfect tense.
Here are the answers to the exercise
- has lived
- have raised
- have gained
- watched
- called
- has not used
- have stayed
- shouted
- has not ordered
- tried
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