Practice links

http://www.ego4u.com/en/cram-up/tests/hadrians-wall

http://www.englisch-hilfen.de/en/exercises/tenses/mix2.htm

http://www.nonstopenglish.com/allexercises/grammar/grammar-tenses.asp

http://www.grammar-quizzes.com/condition3c.html

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