How do we use auxiliary verbs in English? Auxiliary verbs are used in question tags, echo questions, ordinary questions as well as other grammatical structures. Here is an intermediate lesson explaining how to use them and when. https://www.skype-lessons.com/blog/auxiliary-verbs/
PLEASE TRY THIS QUIZ ON THIS GRAMMAR
http://www.quiz.biz/quizz-376839.html
And more on Will's website
http://random-idea-english.blogspot.co.uk/2012/04/emphatic-do-does-did-and-other.html
More lessons and quizzes on my blog
آی-ویدئو