1. THE PERFECT OR COMPLETE TENSES-

2. PRESENT PREFECT TENSE:
*It is used to express an action which happened or completed in past but usually the action which happened or completed at a short time before now (near past) not a very long time before now.
*Specific time such as two years ago, last week or that day is usually not used in the sentences in this tense.

3. • Subject + has/have + NOT + 3rd form of verb + Object
                                Structure of Sentence
           • Subject + has/have + 3rd form of verb + Object
• Subject + has/have + NOT + 3rd form of verb + Object
• Has/have + Subject + 3rd form of verb + Object
Examples        I have eaten meal.        She has learnt a lesson.
I have not eaten meal.       She has not learnt a lesson.
Have I eaten meal?      Has she learnt a lesson?

4. PAST PERFECT TENSE:
*It is used to express an action which has occurred in past (usually, a long time ago)
Example:
I had lived in America.
*Action which has occurred in past before another action in past. 
The students had gone before the teacher came.-

5. • Subject + had + 3rd form of verb + object
                     Structure of sentence.
        • Subject + had + 3rd form of verb + object
Subject + had + not + 3st form of verb + object
• Had + subject + 3rd form of verb + object
Examples.       He had taken the exam last year       A thief had stolen my watch.
He had not taken the exam last year         A thief had not stolen my watch.
Had he taken the exam last year?        Had a thief stolen my watch?

6. John will have gone tomorrow.
FUTURE PERFECT TENSE:
*It is used to express an action which will occur in future and is thought to be completed in future.
*It expresses a sense of completion of an action which will occur in future.
Example:
John will have gone tomorrow.

7. • Subject + will not have + 3rd form of verb + object
Structure of sentence
   • Subject+ will have/Shall have+ 3rd form of verb+object
• Subject + will not have + 3rd form of verb + object
• Will + Subject +have + 3rd form of verb + object
Examples         She will have finished the work by Wednesday.         I Shall have left for home by the time he gets up.
         She will not have finished the work by Wednesday.        I shall not have left for home by the time he gets up
Will she have finished the work by Wednesday? Shall I have left for home by the time he gets up?
       

8. ACTIVITY

9. CONVERT THE GIVEN SENTENCES TO SENTENCES OF PERFECT TENSE
I do not write a letter.
 I sing a song.
They do not read lessons.
I did not kill a snake.
They went to cinema.
 Did he give me a gift.
They have gone to school.
Has it rained.
I will buy a computer tomorrow.
They will come here.
Will they buy a new car.

10. SOLVED I have not written a letter. I have sung a song.
They have not read lessons.
I had not killed a snake.
They have gone to cinema.
 had he given me a gift.
They have gone to school.
Has it rained.
I have bought a computer tomorrow.
They have come here.
Have they bought a new car.