This book has two related purposes. The first is to demonstrate the extent and importance of language play in human life the second is to draw out the implications for applied linguistics and language teaching. Language play should not be thought of as a trivial or peripheral activity, but as central to human thought and culture, to learning, creativity, and intellectual enquiry. It fulfils a major function of language, underpinning the human capacity to adapt: as individuals, as societies, and as a species.