This monograph presents the first comprehensive diachronic account of copular and passive verb constructions in Old and Middle English. Loss of the high-frequency verb weorðan ‘become’ is explained as a result of changing word order in narrative during Middle English. The merger of is ‘is’ and bið ‘shall be, is generally’ into a single suppletive verb is related to the development of a general analytic future shall be. Finally, the co-occurrence of multiple changes led to become and wax crossing a threshold of similarity with existing copulas, from which they analogically adopted full productivity. In explaining each change, the study goes beyond the level of the verb and its complements, drawing attention to analogical networks and the importance of a verb’s embeddedness in clausal and textual environments.
In its radically usage-based approach, treating syntax as emerging from changing frequencies, the study draws attention to some general principles of constructional change, including grammaticalization and lexicalization, by proposing novel parallelisms between linguistic and ecological evolution. Going beyond the view of language change as propagating only in social interaction, each individual’s mental grammar is described as a dynamic ecosystem with hierarchical environments (clausal niches, textual habitats). In this view, the interconnectedness of seemingly unrelated changes, itself resulting from cognitive economy principles, is arguably more decisive in lexical change than is functional competition.