PRESENTS:
http://www.eclecticenglish.com/grammar/PresentContinuous1I.html
http://www.english-grammar-lessons.com/presentsimpleorcontinuous/exercise2.swf

STATIVE VERBS
A video:
http://www.perfect-english-grammar.com/stative-verbs.html

PASTS:
http://www.perfect-english-grammar.com/past-continuous-exercise-3.html
http://www.perfect-english-grammar.com/past-continuous-exercise-4.html
http://www.eclecticenglish.com/grammar/PresentPerfect1C.html
http://www.eclecticenglish.com/grammar/PresentPerfect1E.html
http://www.english-grammar-lessons.com/pastsimpleorcontinuous/exercise3.swf
http://www.english-grammar-lessons.com/pastsimpleorcontinuous/menu.php
http://www.perfect-english-grammar.com/past-perfect-exercise-1.html
http://www.perfect-english-grammar.com/past-perfect-exercise-2.html
http://www.englisch-hilfen.de/en/exercises/tenses/past_perfect_simple_past.htm


FUTURES:
WILL AND GOING TO:
http://www.better-english.com/grammar/willgo.htm
http://www.englisch-hilfen.de/en/exercises/tenses/will_going_to_future.htm
http://www.englishpage.com/verbpage/verbs18.htm
http://www.englishpage.com/verbpage/verbs20.htm
http://www.english-grammar-lessons.com/goingtoorwill/exercise2.swf

FUTURE SIMPLE, SIMPLE VS CONTINUOUS, MIXED:
http://www.ego4u.com/en/cram-up/grammar/future-1-progressive/exercises
http://www.englishpage.com/verbpage/verbs23.htm
http://a4esl.org/q/h/9807/cg-willbe.html

FUTURE PERFECT, SIMPLE VS PERFECT:
http://www.ego4u.com/en/cram-up/grammar/future-2-simple/exercises
http://www.englishpage.com/verbpage/verbs25.htm
http://www.englishpage.com/verbpage/verbs26.htm

FUTURE TIME CLAUSES
http://www.egeacademy.com/blog/exercises/future-time-clauses-when-before-after-as-soon-as-until/
http://www.e-grammar.org/time-clauses/test1-exercise1/
**http://www.e-grammar.org/time-clauses/test1-exercise2/**

MIXED
Simple Present, Present Progressive, Simple Past, Present Perfect, will-future, going to-future
http://www.englisch-hilfen.de/en/complex_tests/tenses1/index.php?action=start2&aufgid=10&Submit=Answer+a+special+paprt
http://www.english-4u.de/tenses_ex2.htm
http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-29177.php
http://www.englishgrammarsecrets.com/pastreview2/exercise1.swf
http://www.english-4u.de/tenses_ex3.htm
http://saberingles.com.ar/exercises/110.html
http://www.englisch-hilfen.de/en/exercises/tenses/mix.htm
http://www.englisch-hilfen.de/en/exercises/tenses/mix2.htm


RELATIVE CLAUSES
http://www.usingenglish.com/quizzes/51.html
http://www.english-area.com/paginas/relativeclauses.htm
http://suz.digitaleschulebayern.de/english/grammar/relpron5.htm
http://baladre.info/english/sedaviwebfront/relative9.htm
http://baladre.info/english/sedaviwebfront/relativematch3.htm
http://www.perfect-english-grammar.com/relative-clauses-exercise-2.html
http://web2.uvcs.uvic.ca/courses/elc/studyzone/410/grammar/adj1.htm

MODALS
Can / could /be able
http://www.perfect-english-grammar.com/modal-verbs-of-ability-exercise-1.html

Mustn't /don't have to /doesn't have to
http://www.perfect-english-grammar.com/modal-verbs-of-obligation-exercise-1.html

Could / could have:
http://www.englishgrammarsecrets.com/could/exercise4.swf
http://www.english-grammar-lessons.com/could/exercise3.swf

Must / have to:
http://www.english-area.com/paginas/musthavetoquiz.htm

Could / would / might :
http://wwwedu.ge.ch/cptic/prospective/projets/anglais/exercises/modalws2.htm

Can / could / may / might / don't have to / can't / should:
http://www.tolearnenglish.com/exercises/exercise-english-1/exercise-english-59.php

Verbs followed by infinitive or gerund
http://www.englisch-hilfen.de/en/exercises/structures/gerund_infinitive.htm
http://www.englisch-hilfen.de/en/exercises/structures/gerund_infinitive2.htm

PASSIVES
Active or passive?
http://a4esl.org/q/h/vm/active-passive.html
Present Perfect Passive:
http://www.perfect-english-grammar.com/passive-exercise-3.html
Future Simple Passive:
http://www.perfect-english-grammar.com/passive-exercise-4.html
Past Simple Passive:
http://www.perfect-english-grammar.com/passive-exercise-2.html
Mixed tenses passive:
http://www.perfect-english-grammar.com/passive-exercise-5.html
Have/get something done (conseguir que alguien haga algo para tí)
http://web2.uvcs.uvic.ca/courses/elc/studyzone/490/grammar/causatives2.htm

CONDITIONALS
http://web2.uvcs.uvic.ca/courses/elc/studyzone/410/grammar/2cond1.htm
http://web2.uvcs.uvic.ca/courses/elc/studyzone/410/grammar/2cond2.htm
http://web2.uvcs.uvic.ca/courses/elc/studyzone/410/grammar/allcnd1.htm

GERUNDS AND INFINITIVES
How to form gerunds
http://web2.uvcs.uvic.ca/courses/elc/studyzone/410/grammar/gerund1.htm
Gerunds or infinitives
http://web2.uvcs.uvic.ca/courses/elc/studyzone/410/grammar/gerinf1.htm
http://web2.uvcs.uvic.ca/courses/elc/studyzone/410/grammar/gerinf2.htm