In linguistics, a
discontinuity occurs when a given word or
phrase is separated from another word or phrase that it modifies in such a manner that a direct connection cannot be established between the two without incurring crossing lines in the tree structure. The terminology that is employed to denote discontinuities varies depending on the theory of syntax at hand. The terms
discontinuous constituent,
displacement,
long distance dependency,
unbounded dependency, and
projectivity violation are largely synonymous with the term
discontinuity. There are various types of discontinuities, the most prominent and widely studied of these being
topicalization,
wh-fronting,
scrambling, and
extraposition.