• Passive sentences
http://www.englisch-hilfen.de/en/grammar_list/passiv.htm
http://www.englisch-hilfen.de/en/exercises_list/alle_grammar.htm
http://www.ego4u.com/en/cram-up/grammar/passive
http://www.oup.com/elt/global/products/englishfile/intermediate/a_grammar/file06/nef_int_grammar06_b01/
http://www.oup.com/elt/global/products/englishfile/intermediate/a_grammar/file06/nef_int_grammar06_c02/

  • Relative sentences
http://www.ego4u.com/en/cram-up/grammar/relative-clauses
http://www.learnenglishfeelgood.com/esl-relative-clauses1.html
http://www.learnenglishfeelgood.com/esl-relative-clauses2.html
http://www.learnenglishfeelgood.com/esl-relative-clauses4.html
http://www.learnenglishfeelgood.com/esl-relative-clauses3.html
http://www.oup.com/elt/global/products/englishfile/intermediate/a_grammar/file06/nef_int_grammar06_c01/
http://www.oup.com/elt/global/products/englishfile/intermediate/a_grammar/file06/nef_int_grammar06_c02/

  • Conditional sentences
http://www.englisch-hilfen.de/en/grammar_list/if.htm
http://www.ego4u.com/en/cram-up/grammar/conditional-sentences
http://www.englisch-hilfen.de/en/exercises_list/alle_grammar.htm
http://www.oup.com/elt/global/products/englishfile/intermediate/a_grammar/file04/nef_int_grammar04_01a/
http://www.oup.com/elt/global/products/englishfile/intermediate/a_grammar/file04/nef_int_grammar04_a02/
http://www.oup.com/elt/global/products/englishfile/intermediate/a_grammar/file04/nef_int_grammar04_b02/
http://www.oup.com/elt/global/products/englishfile/intermediate/a_grammar/file04/nef_int_grammar04_b01/
http://www.oup.com/elt/global/products/englishfile/intermediate/a_grammar/file07/nef_int_grammar07_a01/
http://www.oup.com/elt/global/products/englishfile/intermediate/a_grammar/file07/nef_int_grammar07_a02/