This book shows how grammar helps people communicate and looks at the ways grammar and meaning interrelate. The author starts from the notion that a speaker codes a meaning into grammatical forms which the listener is then able to recover: each word, he shows, has its own meaning and each bit of grammar its own function, their combinations creating and limiting the possibilities for different words. He uncovers a rationale for the varying grammatical properties of different words and in the process explains many facts about English - such as why we can say I wish to go, I wish that he would go, and I want to go but not I want that he would go.