For and Since              

 - You use FOR if you don't have to calculate the period of time, because you have it in the sentence :

I have lived here FOR two months (  you don't have to calculate, you know the period is "two months"  )

 - You use SINCE if you have to calculate the period of time, because you only have the starting point :

I have lived here SINCE 1975 (  you have to calculate now: if you came in 1975 - the starting point - and now it is 2009, then 2009-1975 = 24 years  )

1. I have been living in New York  1 year
2. I haven't seen you a week
3. I have been waiting 12:30.
4. I've lived here  5 years.
5. I've lived here 2003
6.  she came here I've been very nervous
7. She has been married ten years
8. She has been a doctor   1998
9. I have been living in Valencia  last june
10. I haven't seen you  last week
11. Yesterday I studied three hours
12. She has been studying English  two months
13. She has been studying English last January
14. She has been studying English 12.00
15. She has been studying English your birthday
16. She has been studying Englishtwo hours
17. She has been studying English six minutes
18. She has been studying English a long time
19. I've been working here  the last two years.
20. I have loved you the first time I saw you
    

                                                                                                                                                Very easy !!!!