Present Perfect

FORM

[has/have + past participle]

Examples:

• You have seen that movie many times.
• Have you seen that movie many times?
• You have not seen that movie many times.

USE 1 Unspecified Time Before Now

We use the Present Perfect to say that an action happened at an unspecified time before now. The exact time is not important. You CANNOT 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, etc. We CAN use the Present Perfect with unspecific expressions such as: ever, never, once, many times, several times, before, so far, already, yet, etc.

Examples:

• I have seen that movie twenty times.
• I think I have met him once before.
• There have been many earthquakes in California.
• People have traveled to the Moon.
• People have not traveled to Mars.
• Have you read the book yet?
• Nobody has ever climbed that mountain.
• A: Has there ever been a war in the United States?
  B: Yes, there has been a war in the United States.

TOPIC 1 Experience

You can use the Present Perfect to describe your experience. It is like saying, "I have the experience of..." You can also use this tense to say that you have never had a certain experience. The Present Perfect is NOT used to describe a specific event.

Examples:

• I have been to France.
  This sentence means that you have had the experience of being in France. Maybe you have been there once, or several times.
• I have been to France three times.
  You can add the number of times at the end of the sentence.
• I have never been to France.
  This sentence means that you have not had the experience of going to France.
• I think I have seen that movie before.
• He has never traveled by train.
• Joan has studied two foreign languages.
• A: Have you ever met him?
  B: No, I have not met him.

TOPIC 2 Change Over Time

We often use the Present Perfect to talk about change that has happened over a period of time.

Examples:

• You have grown since the last time I saw you.
• The government has become more interested in arts education.
• Japanese has become one of the most popular courses at the university since the Asian studies program was established.
• My English has really improved since I moved to Australia.

TOPIC 3 Accomplishments

We often use the Present Perfect to list the accomplishments of individuals and humanity. You cannot mention a specific time.

Examples:

• Man has walked on the Moon.
• Our son has learned how to read.
• Doctors have cured many deadly diseases.
• Scientists have split the atom.

TOPIC 4 An Uncompleted Action You Are Expecting

We often use the Present Perfect to say that an action which we expected has not happened. Using the Present Perfect suggests that we are still waiting for the action to happen.

Examples:

• James has not finished his homework yet.
• Susan hasn't mastered Japanese, but she can communicate.
• Bill has still not arrived.
• The rain hasn't stopped.

TOPIC 5 Multiple Actions at Different Times

We also use the Present Perfect to talk about several different actions which have occurred in the past at different times. Present Perfect suggests the process is not complete and more actions are possible.

Examples:

• The army has attacked that city five times.
• I have had four quizzes and five tests so far this semester.
• We have had many major problems while working on this project.
• She has talked to several specialists about her problem, but nobody knows why she is sick.

USE 2 Duration From the Past Until Now (Non-Continuous Verbs)

We use the Present Perfect to show that something started in the past and has continued up until now. "For five minutes," "for two weeks," and "since Tuesday" are all durations which can be used with the Present Perfect.

Examples:

• I have had a cold for two weeks.
• She has been in England for six months.
• Mary has loved chocolate since she was a little girl.

!Note It is always for a length of time and since a point in time.

ACTIVE / PASSIVE

Examples:

• Many tourists have visited that castle. Active
• That castle has been visited by many tourists. Passive

http://www.englishpage.com/verbpage/presentperfect.html

Exercises

a ) Write negative sentences in present perfect simple.

The weather was wonderful today. So the children were in the park all afternoon and have not done their household chores:

1. Sarah / not / wash the dishes 
2. Anita / not / clean the kitchen 
3. Maureen and Gavin / not / water the plants 
4. Joey / not / make his bed 
5. David / not / buy milk 

b ) Write sentences in present perfect simple. Place 'never' before the main verb.

1. Fergal / never / sail / on the Pacific. 
2. Rebecca / never / stay / at a five-star hotel 
3. Jason / never / watch / a world-cup final 
4. Rachel and Gareth / never / climb / Mount Kilimanjaro

Simple Past / Present Perfect ?

c ) Using the words in parentheses, complete the text below with the appropriate tenses.

Since computers were first introduced to the public in the early 1980's, technology (change) .......................a great deal. The first computers (be) ................ simple machines designed for basic tasks. They (have, not) ............................  much memory and they (be, not) ....................................very powerful. Early computers were often quite expensive and customers often (pay) ................................... thousands of dollars for machines which actually (do) .......................................  very little. Most computers (be) ...................................... separate, individual machines used mostly as expensive typewriters or for playing games. 

Times (change) ....................................... Computers (become) ............................... powerful machines with very practical applications. Programmers (create) .................................... a large selection of useful programs which do everything from teaching foreign languages to bookkeeping. We are still playing video games, but today's games (become) .....................................  faster, more exciting interactive adventures. Many computer users (get, also) ........................................ on the Internet and (begin) ....................................... communicating with other computer users around the world. We (start) ...........................................to create international communities online. In short, the simple, individual machines of the past (evolve) .................................. into an international World Wide Web of knowledge.

For more exercises visit :

http://www.englishpage.com/verbpage/verbs6.htm

Present perfect simple or continuous ?

Often there is very little difference between the present perfect simple and the present perfect continuous. In many cases, both are equally acceptable.

• They've been working here for a long time but Andy has worked here for even longer.
• I've lived here for 10 years and she has been living here for 12 years.

To emphasize the action, we use the continuous form.

• We've been working really hard for a couple of months.
• She's been having a hard time.

To emphasize the result of the action, we use the simple form.

• I've made fifteen phone calls this morning.
• He's written a very good report.

Look at the difference in these examples.

• I've been reading this book for two months but I've only read half of it. It's very difficult to read.
• She's been trying to convince him for 20 minutes but she hasn't managed to yet.
• They've been talking about this for month and they still haven't found a solution.

When an action is finished and you can see the results, use the continuous form.

• The phone bill is enormous. You've been calling your boyfriend in Australia, haven't you?
• You're red in the face. Have you been running?

When you use the words 'ever' or 'never', use the simple form.

• I don't know them. I've never met them.
• Have you ever heard anything so strange in your life.

http://www.englishgrammarsecrets.com/presentperfectsimpleorcontinuous/menu.php/

Present Perfect Simple or  Present Perfect Progressive ?

1) Result or duration?

2 ) Emphasis on completion or duration?

3 ) Result or side effect?

4 ) Permanent or temporary?

d ) Fill in the correct form (Present Perfect Simple or Present Perfect Progressive).

1. Tom: Hi Ana. I (try)  to ring you several times today. Where (you / be) ?
2. Ana: I (be)  at home all the time. But I (clean)  the house all day, so maybe I didn't hear the phone ring.
3. Tom: (you / clean)  everything now?
4. Ana: No, not yet. I (tidy / not)  up the kitchen yet. But why are you here?
5. Tom: Don't you remember? Jane (invited)  us to her birthday party and we (buy / not)  a present for her yet.
6. Ana: Oh, that's right. (you / find out / already)  what she wants?
7. Tom: Well, she (learn)  Spanish for a year and wants to spend her next holiday in Mexico. Maybe we could get her a guide book.
8. Ana: That's a good idea. There is a good bookshop in the big shopping centre. I (see)  some nice books about Mexico there recently.

For more exercises , visit :

http://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/tests?test1

http://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/tests?test2