1. Past and Present Perfect Tense

2. THE PAST TENSES SIMPLE PAST FUNCTIONS I saw him two weeks ago
I lived there for five years before 2010
I used to get up at 5:30 in the morning
to report an activity or state which can be described to a definite past time.
to describe activity that occurred over a period of time in the past but is now finished.
To describe customary or habitual action in the past.

3. THE PAST TENSES PAST CONTINUOUS FUNCTIONS
What were you doing at 9 last night?
While I was taking a shower, the telephone rang.
I was studying while he was sleeping.
Between 7 and 9 p.m. yesterday, she was talking on the phone.
To indicate that an action was in progress at a definite time in the past.
To indicate the progressive nature of an action that was happening at the same time as another event in the past.
To indicate that two continuous activities were going on at the same time.
To indicate that an activity was going on between two points of time in the past.

4. THE PERFECT TENSES PRESENT PERFECT SIMPLE PAST
I have seen that movie (at some indefinite time in the past)
He has read that book (before time of speaking, but definite time is not known)
Have you ever studied Greek? (indefinite time – at any time in your life from birth up to the moment of speaking)
I have lived in London for two years (I still live there now)
I saw that movie last night (definite time)
He read that book two years ago (definite time)
Yes, I studied Greek when I was in college (definite past time)
I lived in London for two years (no longer live there now - in the past)

5. PRESENT PERFECT TENSES
It is used to indicate an action that took place at an indefinite time or over a period of time in the past (but still has relevance in the present).
It is used to show that an action began in the past and has continued up to the present.
e.g.: I have studied French since 2002.
It is often used with the word ‘just’ to show that an action was completed in the very recent past.
It is used with the word ‘already’ to say something that has happened sooner than expected.

6. PERFECT CONTINUOUS TENSES
It is used for an action which began in the past and is still continuing or has only just finished.
e.g.: I’ve been waiting for two hours.
It emphasizes or exaggerates the progressive nature of the action of the verb or the duration of the action throughout a period of time.
e.g.: Ever since I read the book, I’ve been wanting to meet the author.
A repeated action in the simple present perfect can sometimes be expressed as a continuous action by the present perfect continuous.
e.g.: I’ve written six letters since breakfast (or)
I’ve been writing letters since breakfast.

7. NOW MARCH APRIL MAY JUNE JULY He came to London in April
He worked in USA in March
He was working in USA in March
He came to London in April
John works in London
He is working in London now
He has worked in London for two months (since May)
He has been working in London for two months (since May)
He will work in London until July
He is going to quit his job in the end of July