This book presents a comparative semantic analysis of the internally headed relative clause (IHRC) construction in the framework of Combinatory Categorial Grammar (CCG) based on a sample of a dozen languages. There are two possible CCG analyses of IHRCs, both of which are attested in the data. One of them accounts for material in the head phrase with scope over the whole IHRC (determiners, anaphoric demonstratives, etc.) and for relative pronouns. The other derivation accounts for restrictions on the grammatical relation of the head within the IHRC, for null-headed IHRCs, for the extraposed IHRC construction, and for IHRCs with incorporated heads. The book gives new explanations for the definiteness restriction and for the quantifier restriction on heads, for the Element Constraint, for the restriction against heads embedded in other IHRCs, and for the restriction against wh-words in or extracted from IHRCs. John Enrico did lengthy fieldwork on the three dialects of Haida in Canada and Alaska from the 1970s to the 1990s. He is the author of a number of books and articles on the language.