All aspects of linguistic knowledge are ultimately based on speakers’ experience with lexical expressions, but of course, knowledge of language, notably, grammar, exceeds their memory of particular lexical tokens. It is a standard assumption of the usage-based approach that grammar involves a taxonomic network of constructions ranging from prefabricated strings of lexical expressions to highly abstract schemas. Chapter 4 describes the taxonomic organization of constructions and their development in L1 acquisition and language change. It includes a detailed discussion of current research on statistical grammar learning in infancy, the acquisition of constructions during the preschool years and two case studies on the rise of constructional schemas in language history.

All linguistic elements, e.g., words, phrases and clauses, occur in sequential order. The sequential arrangement of linguistic elements is motivated by conceptual and pragmatic factors, but the strength of sequential relations is primarily determined by automatization or chunking. Since automatization is a gradual process driven by frequency of occurrence, sequential relations vary on a continuum. Moreover, since language unfolds in time, sequential relations have an inherent forward orientation, which is reflected in the fact that listeners are able to “predict” upcoming elements in the unfolding speech stream. Chapter 5 considers the effect of automatization and chunking on the development of linguistic structure and the cognitive organization of grammar. The chapter is divided into two parts. The first part is concerned with research on lexical prefabs and the organization of morphological network models, and the second part considers sequential aspects of constructional schemas and the gradience of constituency.