Simon C. Dik's Theory of Functional Grammar is a systematic treatment and exposition by one of its most distinguished exponents, and compulsory reading for any student of Functional Grammar. Part 1, the first edition of which appeared in 1989, has been revised and updated and is now released together with the publication of part 2. Part 1 sets out the basic principles underlying the theory of Functional Grammar, and discusses the structure of simple (that is, non-derived, non-complex) clauses. The volume does not presuppose any antecedent knowledge of Functional Grammar, nor does it otherwise depend on any sources for a proper understanding of its contents. Part 2, presupposing the contents of part 2, contains a discussion of complex and derived construction types. This volume can thus be used for advanced study of Functional Grammar by those who already have a reasonable knowledge of the basic framework of the theory.