TENSES

TENSE REVIEW 
http://www.englisch-hilfen.de/en/exercises/tenses/mix.htm 
http://www.englisch-hilfen.de/en/exercises/tenses/mix2.htm 
http://theenglishcafe.blogspot.com.es/2009/11/exercise-mixed-tenses.html 
http://www.ego4u.com/en/cram-up/tests/hadrians-wall 
http://www.tolearnenglish.com/english_lessons/mixed-tenses-test 
http://ro.sio.si/~viljenka/mixed_tense.htm
http://www.englishpage.com/verbpage/verbs30finaltest.htm
http://www.englishpage.com/verbpage/verbs29practicetest.htm

http://www.englishpage.com/verbpage/verbtenseintro.html

http://www.ego4u.com/en/cram-up/tests/language-course
http://personales.ya.com/mjandres/archivos/mixedtensessent.htm
http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-8197.php
http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-5050.php
http://www.ihbristol.com/learn-online/exercise-general/intermediate/grammar/more-tenses/221/
http://www.nonstopenglish.com/allexercises/grammar/grammar-tenses.asp
http://www.myenglishpages.com/site_php_files/grammar-exercise-tenses.php
http://www.english-4u.de/grammar_exercises.htm
http://teacher.eduhi.at/english_by/Ex,5,03_1.htm
http://www.tolearnenglish.com/english_lessons/mixed-tenses-test

PAST PERFECT SIMPLE VERSUS PAST PERFECT CONTINUOUS

http://www.myenglishpages.com/site_php_files/grammar-exercise-past-perfect.php

http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-9553.php

http://www.youtube.com/watch?v=oqk1qPmtMRE

http://fdslive.oup.com/www.oup.com/pdf/elt/catalogue/0-19-436577-8.pdf?cc=cz&selLanguage=en


PRESENT PERFECT SIMPLE VERSUS PRESENT PERFECT CONTINUOUS

http://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro

http://www.aulafacil.com/Ingejerc/Lecciones/Ejerc21.htm

http://english-zone.com/verbs/prsperfcont.html

http://a4esl.org/q/f/z/zz28bka.htm