If you’re coming to this book from a traditional grammar or with little or no background in grammar, or if you plan to read only individual chapters, then this chapter was written to orient you to our approach and make your life easier.
We start by discussing words, different senses of what a word is, and the ways that words are categorized. Then show how words can be combined into phrases with heads and dependents, where each phrase category is named after the category of its head word. These phrases build into a special larger phrase called a clause.
With this framework in hand, we move into the core of the chapter. Beginning with §2.3, each of the sections corresponds with a chapter. So, Ch. 3 and §2.3 are Verbs and verb phrases, Ch. 4 and §2.4 are Complements in clauses, etc.
The chapter also includes an appendix explaining the book’s notational conventions.