This is the first book that presents a complete description and analysis of the Spanish suffixes that alter the grammatical behaviour of nouns and adjectives without changing their grammatical category, supporting a fine-grained decomposition of the syntactic area where these word classes are defined. In this monograph the reader will find a detailed empirical description of suffixes for gender, mereological properties of nouns, scalar properties of adjectives and a variety of nominal suffixes expressing actions, measures or locations, as well as an integral Neo-Constructionist analysis of the syntactic structure of the resulting formations. Framed within a Nanosyntactic-oriented framework, this book sheds light on the nature of lexical categories and the components of the low syntactic structure of nouns and adjectives. The book will be useful both to researchers in Spanish linguistics or theoretical morphology and to advanced students of Spanish interested in learning more about the expressive devices that nouns and adjectives allow.