1B AUXILIARY VERBS

For further practice click on the following links:

http://www.englisch-hilfen.de/en/exercises/questions/question_tags3.htm
http://www.englishexercises.net/yytag1.html
http://www.adelescorner.org/grammar/qtags/qtags_mixed_tenses.html
https://elt.oup.com/student/englishfile/upperint/a_grammar/file01/nef_upperint_grammar01_b01?cc=cz&selLanguage=cs