The theory:
MUST
http://ingles-facil.blogspot.com/2008/07/must.html
MAY AND MIGHT
http://ingles-facil.blogspot.com/2008/07/may-and-might.html
CAN, COULD AND BE ABLE TO
http://ingles-facil.blogspot.com/2008/07/can-could-y-b-e-able-to.html
MUST - DON'T HAVE TO
http://www.better-english.com/grammar/mustnt.htm

The exercises:
Must, should or have to:
http://www.aulafacil.com/Ingejerc/Lecciones/Ejerc26.htm
can, could, have to, must, might and should:
http://www.englishpage.com/modals/interactivemodal1.htm
might, must, should, could, have to and ought to:
http://www.englishpage.com/modals/interactivemodal3.htm
could, might, should and would:
http://www.englishpage.com/modals/interactivemodal6.htm

A list of modals and their substitutes:
http://www.ego4u.com/en/cram-up/grammar/modal-verbs
Exercises on these substitutes:
http://www.ego4u.com/en/cram-up/grammar/modal-verbs/exercises
http://www.ego4u.com/en/cram-up/grammar/modal-verbs/exercises?02



PRESENT MODALS
A video on the difference between HAVE TO and NEED:
http://www.engvid.com/modals-of-necessity/
Should, may and can. Some theory and a QUIZ:
http://esl.about.com/library/beginner/bl_bgmodals.htm
Must / Have To - Mustn't / Not Have. Some theory and a QUIZ:
http://esl.about.com/od/intermediate-modals/a/Must-Have-To.htm
Could, must, should, shouldn't, need, might, have to, don't have to, mustn't. Recognise the use:
Quiz 1:
http://esl.about.com/od/grammarintermediate/a/mvb_qone.htm
Quiz 2:
http://esl.about.com/od/grammarintermediate/a/mvb_qtwo.htm


REVISION
Remind the Relative Clauses (Defining and Non-definining
http://www.isabelperez.com/relative.htm

Practise some phrasal verbs:
http://www.isabelperez.com/hotpot/phrasal_v_1.htm
http://www.isabelperez.com/dictionaries/phrasal_2.htm

A video on PUT DOWN, PUT BACK, PUT OFF, PUT UP:
http://www.engvid.com/phrasal-verbs-put/


PERFECT MODALS
A video on Modals of Lost Opportunity (could have, would have, should have):
http://www.engvid.com/could-would-should-modals/

LISTENINGS
A part-time job, the audio
http://www.ompersonal.com.ar/ompodcast/LOINT/loint03.mp3
A part-time job, the exercise
http://www.ompersonal.com.ar/ompodcast/LOINT/loint03.htm
Brian's past
http://www.ompersonal.com.ar/ompodcast/INTER/inter02.htm
I prefer the leather one, the audio
http://www.ompersonal.com.ar/ompodcast/INTER/inter03.mp3
I prefer the leather one, the exercise
http://www.ompersonal.com.ar/ompodcast/INTER/inter03.htm


ALTHOUGH, EVEN THOUGH vs IN SPITE OF, DESPITE
la teorĂ­a:
http://www.ompersonal.com.ar/omgrammar/contraste2.htm
los ejercicios:
http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-5409.php
http://www.hablamejoringles.com/connectors-thoughalthougheven-though-y-in-spite-ofdespite/