* Formation :have / has + past participle form of the verb.
* Usage : - an action began in the past and continues up to now.
- showing interest in the present results of a past action.
- an action that has just finished.
· Words used with the tense : just - yet - already - ever - never - recently - lately - for - since – up to now - so far.
N.B.I- SINCE means " from some definite point in the past till now "
FOR means " a length of time till now ".
N.B.2- The past simple can be used after SINCE with the main verb in the present perfect.
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* Put in the correct tense of the given verbs:
1- 1 ( not see ) you since last Sunday.
* I haven't seen you since last Sunday.
2- She ( not speak ) to me for more than three days.
* She hasn’t spoken to me for more than three days.
3- The policemen already ( find ) the thief.
* The policemen have already found the thief.
4- She just ( go ) to the hairdresser's.
* She has just gone to the hairdresser's.
5- I ( not see ) him since he went to Paris.
* I haven't seen him since he went to Paris.
6- My brother ( not have ) any good rest since last week.
* My brother hasn't had any good rest since last week.
7- You ever ( go ) to London ? Yes, I often ( go ) to London.
* Have you ever gone to London ? Yes, I have often gone to London.
8- I ( wait ) you since four o'clock.
* I have waited you since four o'clock.
9 1 ( not visit ) my grandfather since 1971.
* I haven't visited my grandfather since 1971.
10- She ( be ) ill ( for - since ) a long time.
* She has been ill for a long time.