link for practising grammar exercise

http://www.towson.edu/ows/moduleSVAGR.htm

http://www.cybermocktest.com/bankpo/english_exam.php

http://www.cybermocktest.com/bankpo/english_exam.php

http://www.tcyonline.com/tests/english-grammar/100070/1

http://www.tcyonline.com/CreaTest/index.php?gen_test=yes&testID=673151gen

http://www.examenglish.com/grammar/grammar.html

http://www.ihbristol.com/free-english-exercises/test/esol-smc-modal-verbs

http://www.ego4u.com/en/cram-up/tests/language-course