Present Simple
Extra oefenen met 'Present Simple':
- https://www.englishexercises.org/makeagame/viewgame.asp?id=4599
- https://www.englisch-hilfen.de/en/exercises/tenses/simple_present_negation2.htm
- https://agendaweb.org/exercises/verbs/present-negative
- http://elovivo.com/introenglish/en/intro_english/lessons_wordlist/basic_english_lesson_03/lesson03b_ex.html
- http://www.eflnet.com/grammar/presentagreement.php