http://grammar.uoregon.edu/toc.html

http://online.ohlone.cc.ca.us/~mlieu/

http://www.edufind.com/english/grammar/index.cfm

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

http://www.smic.be/smic5022/exercisesgrammar.htm

http://owl.english.purdue.edu/handouts/grammar/

http://grammar.ccc.commnet.edu/grammar/quiz_list.htm