Links to practise Simple Present
http://www.saberingles.com.ar/curso/lesson06/06.html
http://pagesperso-orange.fr/michel.barbot/cap/do_does/do2.htm
http://www.englisch-hilfen.de/en/exercises/tenses/do_does2.htm
http://www.better-english.com/easier/inonat.htm
http://www.members.iinet.net.au/~adelegc/grammar/present_simple/pres_sim_quests1.html
http://a4esl.org/q/f/z/zz87mca.htm
http://a4esl.org/q/h/lb/psnv.html
http://www.isabelperez.com/happy/tenses/exercises/pres_simple_quest1.htm
http://www.oup.com/elt/global/products/inenglish/elementary/a_grammar/ine_elementary_grammar11/
Frequency Adverbs
http://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/adverbs_of_frequency.htm
http://esl.lbcc.cc.ca.us/eesllessons/adverbfreq/adfreqz.htm
http://www.miguelmllop.com/practice/beginners/grammar/frequencyadverbs1.htm
http://serveng/frequency adverbs.htm
http://serveng/yesno.htm
http://serveng/wh-questions.htm
http://serveng/seasons.htm
http://www.cyberteacher.it/esercizi/ing_2adverbs.htm