The Present Perfect is used to describe

The Present Perfect
The present perfect is used to describe

• 
  An action or situation that started in the past and continues in the present. I have lived in Bristol since 1984 (= and I still do.)
  
• 
  An action performed during a period that has not yet finished. She has been to the cinema twice this week (= and the week isn't over yet.)
  
• 
  A repeated action in an unspecified period between the past and now. We have visited Portugal several times.
  
• 
  An action that was completed in the very recent past, expressed by 'just'. I have just finished my work.
  
• 
  An action when the time is not important. He has read 'War and Peace'. (= the result of his reading is important)
  

Note: When we want to give or ask details about when, where, who, we use the simple past. Read more about choosing between the present perfect and the simple past tenses.
Forming the present perfect
The present perfect of any verb is composed of two elements : the appropriate form of the auxiliary verb to have (present tense), plus the past participle of the main verb. The past participle of a regular verb is base+ed, e.g. played, arrived, looked. For irregular verbs, see the Table of irregular verbs in the section called 'Verbs'.
The Past Perfect
The past perfect, also called the pluperfect, is a verb tense used to talk about actions that were completed before some point in the past.
Example : We were shocked to discover that someone had graffitied “Tootles was here” on our front door. We were relieved that Tootles had used washable paint.
The past perfect formula
The formula for the past perfect tense is had + [past participle]. It doesn’t matter if the subject is singular or plural; the formula doesn’t change.
When to use the past perfect
So what’s the difference between past perfect and simple past? When you’re talking about some point in the past and want to reference an event that happened even earlier, using the past perfect allows you to convey the sequence of the events. It’s also clearer and more specific. Consider the difference between these two sentences:
Example :We were relieved that Tootles used washable paint. We were relieved that Tootles had used washable paint.
It’s a subtle difference, but the first sentence doesn’t tie Tootles’s act of using washable paint to any particular moment in time; readers might interpret it as “We were relieved that Tootles was in the habit of using washable paint.” In the second sentence, the past perfect makes it clear that you’re talking about a specific instance of using washable paint.
Another time to use the past perfect is when you are expressing a condition and a result:
Example : If I had woken up earlier this morning, I would have caught Tootles red-handed.
The past perfect is used in the part of the sentence that explains the condition (the if-clause).Most often, the reason to write a verb in the past perfect tense is to show that it happened before other actions in the same sentence that are described by verbs in the simple past tense. Writing an entire paragraph with every verb in the past perfect tense is unusua