4ESO - MODAL VERBS

http://englishteachera.blogspot.com.es/2012/03/can-could-will-be-able-to.html

http://www.englishexercises.org/makeagame/viewgame.asp?id=1793

http://www.englishexercises.org/makeagame/viewgame.asp?id=6270

http://www.englishexercises.org/makeagame/viewgame.asp?id=2229

http://www.englishpage.com/modals/interactivemodal1.htm