Present perfect with for&since

Explanation present perfect. Short youtube film.
http://www.youtube.com/v/hgcR9fiJ9Bg
 

Explanation when to use for and since
https://www.englishclub.com/grammar/verb-tenses_present-perfect_fs.htm
 

Practice

http://www.eclecticenglish.com/grammar/PresentPerfect1D.html

http://www.englishexercises.org/makeagame/viewgame.asp?id=5876

http://www.english-4u.de/for_since_ex2.htm