Movement and Displacement

Movement is the syntactic operation by which a constituent is displaced from the position where it is interpreted to another position in the sentence, leaving a trace or copy behind.

Definition

Movement, or displacement, is the syntactic relation between the position in which a constituent is pronounced and a distinct position with which it is associated for interpretation, modelled as the relocation of the constituent and the residue it leaves behind.

Scope

This topic covers the displacement property of language: the major movement types (head movement, A-movement, and A-bar movement such as wh-movement), the traces or copies movement leaves, and the locality constraints (islands) that restrict it. It does not cover base phrase structure, constituency tests, or specific theoretical frameworks, which are treated in neighbouring topics.

Core questions

• Why do constituents appear in positions other than where they are interpreted?
• What types of movement does syntax employ?
• What constraints limit how far and across what boundaries movement can apply?
• What does a moved element leave behind in its original position?

Key concepts

• wh-movement
• A-movement versus A-bar movement
• head movement
• trace and copy
• island constraints
• locality

Key theories

Move-alpha and traces

The Government and Binding view that a single general operation, Move-alpha, relocates constituents and leaves coindexed traces, with the resulting chains governed by general principles.

Island constraints on extraction

Ross's discovery that movement is blocked out of certain configurations (islands), such as complex noun phrases and coordinate structures, motivating locality conditions on displacement.

History

Displacement was handled by construction-specific transformations in early generative grammar. Ross (1967) uncovered general constraints (islands) on extraction, prompting a search for principles rather than rules. Chomsky (1981) reduced transformations to the single schema Move-alpha constrained by independent principles. The Minimalist Program later recast movement as an instance of Merge (internal Merge), with copies replacing traces.

Debates

Traces versus copies

Whether a moved constituent leaves an empty trace or a full copy in its original position, a choice with consequences for reconstruction effects and the interpretation of displaced elements.

Key figures

• Noam Chomsky
• John Robert Ross
• Andrew Carnie

Seminal works

• ross1967
• chomsky1981
• carnie2013

Frequently asked questions

What is a classic example of movement?

In the question 'What did you read?', the object 'what' is interpreted as the thing read by the verb but is pronounced at the front of the clause. The gap after 'read' marks where it is interpreted, illustrating wh-movement.

What is a syntactic island?

An island is a structure out of which a constituent cannot be moved. For example, you cannot question out of a relative clause, which is why a sentence like 'What did you meet the man who bought?' is ill-formed.