Empty categoryIn linguistics, an empty category, which may also be referred to as a covert category, is an element in the study of syntax that does not have any phonological content and is therefore unpronounced. Empty categories exist in contrast to overt categories which are pronounced. When representing empty categories in tree structures, linguists use a null symbol (∅) to depict the idea that there is a mental category at the level being represented, even if the word(s) are being left out of overt speech.
Syntactic movementSyntactic movement is the means by which some theories of syntax address discontinuities. Movement was first postulated by structuralist linguists who expressed it in terms of discontinuous constituents or displacement. Some constituents appear to have been displaced from the position in which they receive important features of interpretation. The concept of movement is controversial and is associated with so-called transformational or derivational theories of syntax (such as transformational grammar, government and binding theory, minimalist program).
Principles and parametersPrinciples and parameters is a framework within generative linguistics in which the syntax of a natural language is described in accordance with general principles (i.e. abstract rules or grammars) and specific parameters (i.e. markers, switches) that for particular languages are either turned on or off. For example, the position of heads in phrases is determined by a parameter. Whether a language is head-initial or head-final is regarded as a parameter which is either on or off for particular languages (i.
X-bar theoryIn linguistics, X-bar theory is a model of phrase-structure grammar and a theory of syntactic category formation that was first proposed by Noam Chomsky in 1970 reformulating the ideas of Zellig Harris (1951,) and further developed by Ray Jackendoff (1974, 1977a, 1977b), along the lines of the theory of generative grammar put forth in the 1950s by Chomsky. It attempts to capture the structure of with a single uniform structure called the X-bar schema, basing itself on the assumption that any phrase in natural language is an XP (X phrase) that is headed by a given X.
