"1) Workbook Exercises (WBE): This workbook contains enrichment and additional practice exercises that go along with each chapter in the book. You can check your own answers against the answer key at the end of each chapter. 2) General Problem Sets (GPS) (in the main textbook): You can do the general problem sets at the end of each chapter in the main textbook. I'm sorry but the answers to these questions are not made available to students. The reason for this is that many instructors use these problem sets as a means for student evaluation. Providing the answers to these would be counterproductive! If you are using the textbook for self-study or your instructor isn't using the problem sets for evaluation, I encourage you to find a linguistics professor or linguistics (post-)graduate student who can help you with determining if you are on the right track with these. 3)If you are an advanced student or a graduate student, I strongly encourage you to try the Challenge Problem Sets (CPS) at the end of each chapter in the main textbook. These problem sets are designed to make you think critically about the presentation in the text and to think about alternatives and problems that exist for the theory. Again the answers to these cannot be distributed to students"--