I am working with a 4th grader who has PDD and a cognitive disability. We have worked on 'why' questions for 2 years. He is able to answer 'why' questions that he has memorized but he still does not have the concept of what 'why' means and cannot answer novel 'why' questions. His mother says I have to find "a new way to teach him why questions." Any ideas for teaching this??? Thank you!