structuredepend

Structuredepend, also called structure dependence, is a concept in linguistics referring to the principle that certain syntactic transformations rely on the hierarchical structure of sentences rather than on linear word order. The term is commonly encountered in discussions of generative grammar and related theories of syntax.

Historically, structuredepend was highlighted by Noam Chomsky in the 1960s as a critique of early finite-state models of language. He argued that many long-distance dependencies, such as the formation of questions by moving a wh-word, could not be captured by rules based solely on adjacent words; instead, their legality is determined by the underlying phrase structure, notably the relations among CPs and IPs. Thus, the relevant rules are structure-dependent rather than purely local.

In practice, structuredepend provides an account of why certain extractions occur and others do not. For example, English wh-movement moves a wh-phrase to the edge of the sentence, but only to the specifier of the appropriate CP in the hierarchical structure, not simply to the left by a fixed distance. This captures both the possibility of forming grammatical questions and the constraints imposed by islands and other structural configurations. The concept has been influential across generations of syntactic theory, from Government and Binding to the Minimalist Program, and continues to inform analyses of cross-linguistic data and long-distance dependencies.

While structuredepend remains a foundational idea, some frameworks explore additional mechanisms, such as feature-driven movements and locality constraints, to account for observed phenomena. The term is used in literature as shorthand for the broader principle that structural, not merely linear, factors govern certain grammatical transformations.