Present Perfect - Quando usa-lo?

1. Nós usamos o Present Perfect para falarmos de coisas que ocorreram em nossa vida, mas sem citar a época
   Examples
      I have been abroad two times.
      Anna has never broken a leg.
      Have you ever eaten sushi?
Tip! Normalmente se usa never e ever para falar sobre estes fatos. 


2. Nós usamos o Present Perfect Tense para falar sobre algo que ocorreu no passado e que ainda perdura.
   Examples
      I have been a teacher for more than ten years.
      We haven't seen Janine since Friday.
      How long have you been at this school?
Tip! Normalmente se usa  since e for nestas situações.


3. Nos usamos o  Present Perfect Tense tpara falar de coisas que ocorreram no passado e que me trouxeram alguma consequência para o presente.
   Examples
      I have lost my wallet. = I don't have it now.
      Jimmy has gone to South America. = He isn't here now.
      Have you finished your homework? = Is your homework ready?
Tip! Normalmente se usa just, already e yet com o Present Perfect Tense para estes casos. 

http://www.eclecticenglish.com/grammar/PresentPerfect1A.html

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


http://www.englishexercises.org/makeagame/viewgame.asp?id=839
http://s.mound.free.fr/skyblues67/presentperfect/presperfect1.htm
http://www.ego4u.com/en/cram-up/grammar/present-perfect-simple/exercises?03
http://www.englisch-hilfen.de/en/complex_tests/present_perfect1/index.php?action=start2&aufgid=12&Submit=Answer+a+special+part
http://www.englisch-hilfen.de/en/complex_tests/present_perfect1/index.php?action=start2&aufgid=12&Submit=Answer+a+special+part
http://www.ego4u.com/en/cram-up/grammar/present-perfect-simple/exercises?07