UNIT 5: PRACTISE THE MODAL VERB CAN/CAN'T!

https://elt.oup.com/student/englishfile/elementary/a_grammar/file04/grammar04_01a?cc=us&selLanguage=enhttps://elt.oup.com/student/englishfile/elementary/a_grammar/file04/grammar04_a02?cc=us&selLanguage=en
http://www.esl-lounge.com/student/grammar/1g102-elementary-can-cant-exercise.php
http://www.englisch-hilfen.de/en/exercises/modals/can4.htm