left dislocation

In GRAMMATICAL description, a type of SENTENCE in which one of the CONSTITUENTS appears in INITIAL position and its CANONICAL position is filled by a PRONOUN or a full LEXICAL NOUN PHRASE with the same REFERENCE, e.g. John, I like him/the old chap. In TRANSFORMATIONAL grammar, left dislocation sentences have been contrasted with TOPICALIZATION sentences. The former are analyzed as BASE-generated and the latter as involving MOVEMENT.