Present perfect simple

1. Present perfect

They have painted their bedroom.

She has written several novels.

2. Structure of present perfect 

• Affirmative form

  Subject	auxiliarY	Verb (past participle)	Examples
  I	have 've	been	I have been to Mexico.
  You			You have been to Mexico.
  He	has 's		He has been to Mexico.
  She			She has been to Mexico.
  It			It has been to Mexico.
  We	have 've		We have been to Mexico.
  You			You have been to Mexico.
  They			They have been to Mexico.

  Remember that with regular verbs we form the past participle by adding -ed to the end of the verb, while with irregular verbs we have to look at the 3rd column of the list of irregular verbs.
• Negative form

  Subject	auxiliarY	Verb (past participle)	Examples
  I	have not haven't	been	I haven't been to Mexico.
  You			You haven't been to Mexico.
  He	has not hasn't		He hasn't been to Mexico.
  She			She hasn't been to Mexico.
  It			It hasn't been to Mexico.
  We	have not haven't		We haven't been to Mexico.
  You			You haven't been to Mexico.
  They			They haven't been to Mexico.

• Interrogative form

  auxiliarY	Subject	Verb (past participle)	Examples
  Have	I	been?	Have I been to Mexico?
  	you		Have you been to Mexico?
  Has	he		Has he been to Mexico?
  	she		Has she been to Mexico?
  	it		Has it been to Mexico?
  Have	we		Have we been to Mexico?
  	you		Have you been to Mexico?
  	they		Have they been to Mexico?

Interrogative sentences in present perfect also have their own short answers.

Have you locked the door? Yes, I have.

Has he broken the window? No, he hasn't.

3. How is the present perfect used?

The present perfect is used for:

• Actions performed at undetermined point in the past that have a result in the present.  It is not important to know exactly when the action occurred.
  
  She has made her bed.

  The bed was made at some point in the past, we do not know when. The result in the present is that the bed is made.

  He has watered the plants.

  At some point in the past he watered the plants. The result is that the plants have water now.
• Experiences
  .
  She has flown in a balloon, she has done parachuting and she has swum with dolphins.

  She did all these activities at some point in the past, but the time she did them is not mentioned because it is not relevant in this context. That is, she emphasizes the action but not the specific moment when the action took place.
• Repeated actions that have taken place at different times in the past, that is, that have occurred more than once.
  
  I have lost my wallet four times.

  In this case, the action of losing his wallet has taken place repeatedly. The important thing is the action, not when it happened.

  I have seen the film twice.

  He visto la película dos veces.

  In this case, the action has taken place a couple of times in the past. Again, the important thing is not when it happened but the action itself (see the movie).
• Actions that began at some specific point in the past and continue in the present.
  
  Mary has worked in a bank since 1999.

  Mary started working at the bank at one point in the past (1999) and she is still working there today.

4. Time expressions with the present perfect

With the present perfect the following time expressions are usually used:

• JUST

  The action took place a short time ago and it's finished. It is mainly used in affirmative sentences and it is placed between the auxiliary verb have and the main verb.

  Sally has just washed her hair.

  They have just done an exam.
• ALREADY

  The action took place at some point before now or before the expected time. It is used in affirmative sentences and it can go between the auxiliary verb have and the main verb, or at the end of a sentence.

  
  

  Mary has already washed the dishes.

  We have already been here.
• YET

  In interrogative sentences it is used to ask whether something that was expected to happen has occurred. In negative sentences it is used to express that an action that should have happened has not taken place.  It goes at the end of a sentence.

  
  

  My sister hasn't arrived in London yet.

  Has Mr. Jones corrected the exams yet?
• FOR
  It shows duration, that is, how long an action lasts or continues. The action began at a particular time in the past and continues into the present.
  

  We have been married for two years.

  She has lived in London for 12 years.
• SINCE
  It indicates when the action began and covers the period of time between that particular moment in the past and the present.
  

  I haven't smoked since last week.

  She has worked in the company since April.
• EVER
  It means at any time in the past. It is usually used to ask about experiences and it is placed between the subject and the main verb.
  

  Have you ever eaten snake meat?

  Has he ever played volleyball?
• HOW LONG
  It is mainly used in interrogative sentences to ask about the period of time that has passed since the action began until the present moment.
  

  How long have you been together?

  As we can see, this example refers to the time that has passed between the time this couple started dating and the present day.

  How long has Paul taught in this school?

  As we can see, this example refers to the time that has passed since Paul started teaching in the school until today.

Remember!