1. Do these exercises

http://www.englishclub.com/grammar/verbs-m_infinitive-ing_quiz.htm

http://www.englishclub.com/grammar/verbs-gerunds_quiz.htm

http://www.englisch-hilfen.de/en/exercises/structures/gerund_infinitive.htm

http://www.usingenglish.com/handouts/339.html

http://www.ego4u.com/en/cram-up/tests/infinitive-gerund-4

2. Practice writing this dictation.http://www.englishclub.com/listening/dictations-s-people.htm

The Canadian College of English Language