PRESENT PERFECT

http://www.agendaweb.org/verbs/present_perfect-exercises.html

http://www.agendaweb.org/verbs/present_perfect-tense-exercises.html

http://www.agendaweb.org/verbs/present-perfect-simple.html

http://www.agendaweb.org/verbs/present-perfect-simple-exercises.html

http://www.agendaweb.org/verbs/present-perfect.html

http://www.agendaweb.org/verbs/present-perfect-simple-past-simple-exercises.html

FOR AND SINCE

http://www.agendaweb.org/verbs/present-perfect-simple-exercises.html

http://www.agendaweb.org/verbs/present-perfect-past-simple.html

http://www.agendaweb.org/verbs/present_perfect_continuous-exercises.html

http://www.agendaweb.org/verbs/present_perfect_progressive-exercises.html