Present perfect tense with for and since

1. PRESENT PERFECT TENSE
WITH FOR AND SINCE 
Adriana Vărzaru

2. WHEN IS IT USED?
We use Present Perfect tense to talk about action
which started in the past and continues up to the
present.
Examples 
   I have had this computer for about a year. 
   How long have you been at this school? 
   I haven't seen Julia since September.

3. FOR OR SINCE
We use for with a period of time, for example: a
few days, half an hour, two years.
We use since with the time when the action
started, for example: last year, June 8, I met you.

4. EXERCISE. DO WE
USE FOR OR SINCE WITH THE
FOLLOWING TIME REFERENCES?
I haven't phoned home   Christmas.
We've been here   nine o'clock.
I have worked for International House   more
than eight years.
I haven't visited my home town   I left school.
I haven't been to the cinema   ages.
I have studied non-stop   9.15.
I have had a driving licence   I was eighteen.
She hasn't had a day off   1999.
Johan has been in England   more than two
weeks now.

5. NOTE:
For and since can both be used with the past
perfect.
Since can only be used with perfect
tenses, for can also be used with the simple past.