tercero C review

simple past
http://www.englishexercises.org/makeagame/viewgame.asp?id=2252
http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises

Present Perfect 
http://www.englisch-hilfen.de/en/exercises/tenses/present_perfect_statements.htm
http://www.ego4u.com/en/cram-up/grammar/present-perfect-simple/exercises?03

Present Perfect vs. Simple past 
http://www.usingenglish.com/quizzes/228.html




Simple Present
http://www.really-learn-english.com/simple-present-exercises.html#01
http://www.really-learn-english.com/simple-present-exercises.html#06


Present Continuous 
http://www.eclecticenglish.com/grammar/PresentContinuous1F.html
http://www.isabelperez.com/happy/tenses/exercises/pres_cont_quest1.htm

Simple Present / Present  Continuous
http://www.impact-english.com/members/Grammar_Practice/Always/test-grammar/gr_prac_use-PPrg-gen.htm