This book arises directly from my experiences of introducing functional grammar to a number of different groups of students, teachers and researchers. Like any model that attempts to offer a global view of how language works, functional grammar is complex, and students may be understandably daunted not only by the seemingly abstruse explanations but simply by the amount of new terminology. What I have tried to do is to set out the approach from the point of view of readers who are not familiar with this way of looking at language, and who may, indeed, have little background in linguistic analysis generally. This involves describing the theoretical and practical aspects of the functional grammar model in as accessible a way as possible; but it also involves trying to make clear the reasons why the model is as itis, at all levels- from why a. functional approach is adopted to why one particular analysis of a wording is preferable to another.