Question tags are one of the most familiar structures for students of English but there are other uses of auxiliary and modal verbs which are by no means less common. These verbs are also used:
-In short answers:
A. "Do you like him?" B. "Yes, I do"
-To avoid repetition:
"I love sunbathing on the beach, but my husband doesn´t"
-To show agreement with so and neither:
A. "She can´t understand politicians" B. "Neither can I!"
-With echo questions:
A. "I went to a psychic last weekend" B. "Did you?"-To show emphasis:
A bit confusing, isn´t it? Ok, then try and have a look at the following PowerPoint presentation and I do hope this murky matter will become crystal clear for you!
You can get some practice by clicking on the following links:
Echo questions: http://personales.ya.com/englishcourse/6.3.5.htm
So & neither: http://www.usingenglish.com/quizzes/68.html
If you still feel you need further practice, just google what you want. Don´t forget that on the net there are plenty of resources at your fingertips!