Form 8c. Gerund - Infinitive

For practicing: https://www.ego4u.com/en/cram-up/grammar/infinitive-gerund; http://www.englisch-hilfen.de/en/exercises_list/gerund_infinitiv.htm; http://www.perfect-english-grammar.com/gerunds-and-infinitives-exercise-1.html.

Form 8a. Passive voice

For practicing: https://www.ego4u.com/en/cram-up/grammar/passive/exercises?simple-present; http://www.englisch-hilfen.de/en/exercises/active_passive/sentences_gaps.htm; http://www.perfect-english-grammar.com/passive-exercise-5.html; https://learnenglish.britishcouncil.org/en/english-grammar/verbs/active-and-passive-voic; http://www.learnenglishfeelgood.com/esl-passive-voice-exercise2.html.

Form 8c. Relative clauses. WHO WHERE WHICH

For practicing: http://www.englishexercises.net/yywhowhich.html;
https://www.ego4u.com/en/cram-up/vocabulary/who-which;
http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-62912.php.

Form 8a. Past Perfect

For practicing: http://www.perfect-english-grammar.com/past-perfect-exercise-1.html;
http://www.englisch-hilfen.de/en/exercises/tenses/past_perfect_simple_past.htm.