conditionals

http://www.englisch-hilfen.de/en/exercises/if_clauses/type_1_statements.htm

http://www.englisch-hilfen.de/en/exercises/if_clauses/type_1_negation.htm

http://www.englisch-hilfen.de/en/exercises/if_clauses/type_1_mix3.htm

http://www.englisch-hilfen.de/en/exercises/if_clauses/type_1_mix.htm

http://www.ego4u.com/en/cram-up/grammar/conditional-sentences/type-1

http://www.ego4u.com/en/cram-up/grammar/conditional-sentences/type-1/exercises

http://www.englishpage.com/conditional/conditional1.htm