Present and Past simple

Practicing is never too much...

Present

http://worldofenglish.com/exe.php?Tenses/Simple/Present/build.tra
http://www.isabelperez.com/pr-simple.htm
http://www.isabelperez.com/pr-simple-neg.htm
http://www.isabelperez.com/q1.htm
http://www.isabelperez.com/q-a-easy.htm
http://www.isabelperez.com/presentne.htm

Past

http://worldofenglish.com/exe.php?Tenses/Simple/Past/forms.mem
http://www.isabelperez.com/happy/tenses/past_simple.htm
http://www.isabelperez.com/exer/pastmix.htm
http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises?04
http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises?02
http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises?05

Best wishes,
André