will going to

http://www.englishexercises.org/makeagame/viewgame.asp?id=3135
http://www.better-english.com/grammar/willgo.htm
http://www.englishgrammarsecrets.com/goingtoorwill/exercise2.html
http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-17802.php
http://www.montsemorales.com/gramatica/Tooenough.htm

modals

http://baladre.info/english/sedaviwebfront/mustshould.htm
http://s.mound.free.fr/skyblues67/modals/schoollife.htm
http://www.english-grammar-lessons.com/could/exercise3.swf
http://teacher.schule.at/tom-schoftner/drw_files/modal_verbs_cannot_could_not_1.htm
http://www.englishgrammarsecrets.com/should/exercise1.swf
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http://www.learnenglishfeelgood.com/esl-mixed-modals1.html