In linguistics, syntax is the study of how words and morphemes combine to form larger units such as phrases and sentences. Central concerns of syntax include word order, grammatical relations, hierarchical sentence structure (constituency), agreement, the nature of crosslinguistic variation, and the relationship between form and meaning (semantics). Diverse approaches, such as generative grammar and functional grammar, offer unique perspectives on syntax, reflecting its complexity and centrality to understanding human language.
A syntactic category is a syntactic unit that theories of syntax assume. Word classes, largely corresponding to traditional parts of speech, are syntactic categories. In phrase structure grammars, the phrasal categories are also syntactic categories. Dependency grammars, however, do not acknowledge phrasal categories.
In grammar, a phrase—called expression in some contexts—is a group of words or singular word acting as a grammatical unit. For instance, the English expression "the very happy squirrel" is a noun phrase which contains the adjective phrase "very happy". Phrases can consist of a single word or a complete sentence. In theoretical linguistics, phrases are often analyzed as units of syntactic structure such as a constituent. There is a difference between the common use of the term phrase and its technical use in linguistics. In common usage, a phrase is usually a group of words with some special idiomatic meaning or other significance, such as "all rights reserved", "economical with the truth", "kick the bucket", and the like. It may be a euphemism, a saying or proverb, a fixed expression, a figure of speech, etc.. In linguistics, these are known as phrasemes.
Phrase structure rules are a type of rewrite rule used to describe a given language's syntax and are closely associated with the early stages of transformational grammar, proposed by Noam Chomsky in 1957. They are used to break down a natural language sentence into its constituent parts, also known as syntactic categories, including both lexical categories and phrasal categories. A grammar that uses phrase structure rules is a type of phrase structure grammar. Phrase structure rules as they are commonly employed operate according to the constituency relation, and a grammar that employs phrase structure rules is therefore a constituency grammar; as such, it stands in contrast to dependency grammars, which are based on the dependency relation.
A noun phrase – or NP or nominal (phrase) – is a phrase that usually has a noun or pronoun as its head, and has the same grammatical functions as a noun. Noun phrases are very common cross-linguistically, and they may be the most frequently occurring phrase type.
A parse tree or parsing tree is an ordered, rooted tree that represents the syntactic structure of a string according to some context-free grammar. The term parse tree itself is used primarily in computational linguistics; in theoretical syntax, the term syntax tree is more common.
In 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, along the lines of the theory of generative grammar put forth in the 1950s by Chomsky. It attempts to capture the structure of phrasal categories with a single uniform structure called the X-bar schema, basing itself on the assumption that any phrase in natural language is an XP that is headed by a given syntactic category X. It played a significant role in resolving issues that phrase structure rules had, representative of which is the proliferation of grammatical rules, which is against the thesis of generative grammar.
In linguistics, a determiner phrase (DP) is a type of phrase headed by a determiner such as many. Controversially, many approaches take a phrase like not very many apples to be a DP, headed, in this case, by the determiner many. This is called the DP analysis or the DP hypothesis. Others reject this analysis in favor of the more traditional NP analysis where apples would be the head of the phrase in which the DP not very many is merely a dependent. Thus, there are competing analyses concerning heads and dependents in nominal groups. The DP analysis developed in the late 1970s and early 1980s, and it is the majority view in generative grammar today.
In linguistics, the head or nucleus of a phrase is the word that determines the syntactic category of that phrase. For example, the head of the noun phrase boiling hot water is the noun water. Analogously, the head of a compound is the stem that determines the semantic category of that compound. For example, the head of the compound noun handbag is bag, since a handbag is a bag, not a hand. The other elements of the phrase or compound modify the head, and are therefore the head's dependents. Headed phrases and compounds are called endocentric, whereas exocentric ("headless") phrases and compounds lack a clear head. Heads are crucial to establishing the direction of branching. Head-initial phrases are right-branching, head-final phrases are left-branching, and head-medial phrases combine left- and right-branching.
Dependency grammar (DG) is a class of modern grammatical theories that are all based on the dependency relation and that can be traced back primarily to the work of Lucien Tesnière. Dependency is the notion that linguistic units, e.g. words, are connected to each other by directed links. The (finite) verb is taken to be the structural center of clause structure. All other syntactic units (words) are either directly or indirectly connected to the verb in terms of the directed links, which are called dependencies. Dependency grammar differs from phrase structure grammar in that while it can identify phrases it tends to overlook phrasal nodes. A dependency structure is determined by the relation between a word and its dependents. Dependency structures are flatter than phrase structures in part because they lack a finite verb phrase constituent, and they are thus well suited for the analysis of languages with free word order, such as Czech or Warlpiri.
The term phrase structure grammar was originally introduced by Noam Chomsky as the term for grammar studied previously by Emil Post and Axel Thue. Some authors, however, reserve the term for more restricted grammars in the Chomsky hierarchy: context-sensitive grammars or context-free grammars. In a broader sense, phrase structure grammars are also known as constituency grammars. The defining character of phrase structure grammars is thus their adherence to the constituency relation, as opposed to the dependency relation of dependency grammars.
A sentence diagram is a pictorial representation of the grammatical structure of a sentence. The term "sentence diagram" is used more when teaching written language, where sentences are diagrammed. The model shows the relations between words and the nature of sentence structure and can be used as a tool to help recognize which potential sentences are actual sentences.
In theoretical linguistics, a distinction is made between endocentric and exocentric constructions. A grammatical construction is said to be endocentric if it fulfils the same linguistic function as one of its parts, and exocentric if it does not. The distinction reaches back at least to Bloomfield's work of the 1930s, who based it on terms by Pāṇini and Patañjali in Sanskrit grammar. Such a distinction is possible only in phrase structure grammars, since in dependency grammars all constructions are necessarily endocentric.
Lucien Tesnière was a prominent and influential French linguist. He was born in Mont-Saint-Aignan on May 13, 1893. As a senior lecturer at the University of Strasbourg (1924) and later professor at the University of Montpellier (1937), he published many papers and books on Slavic languages. However, his importance in the history of linguistics is based mainly on his development of an approach to the syntax of natural languages that would become known as dependency grammar. He presented his theory in his book Éléments de syntaxe structurale, published posthumously in 1959. In the book he proposes a sophisticated formalization of syntactic structures, supported by many examples from a diversity of languages. Tesnière died in Montpellier on December 6, 1954.
In linguistics, an argument is an expression that helps complete the meaning of a predicate, the latter referring in this context to a main verb and its auxiliaries. In this regard, the complement is a closely related concept. Most predicates take one, two, or three arguments. A predicate and its arguments form a predicate-argument structure. The discussion of predicates and arguments is associated most with (content) verbs and noun phrases (NPs), although other syntactic categories can also be construed as predicates and as arguments. Arguments must be distinguished from adjuncts. While a predicate needs its arguments to complete its meaning, the adjuncts that appear with a predicate are optional; they are not necessary to complete the meaning of the predicate. Most theories of syntax and semantics acknowledge arguments and adjuncts, although the terminology varies, and the distinction is generally believed to exist in all languages. Dependency grammars sometimes call arguments actants, following Lucien Tesnière (1959).
Merge is one of the basic operations in the Minimalist Program, a leading approach to generative syntax, when two syntactic objects are combined to form a new syntactic unit. Merge also has the property of recursion in that it may be applied to its own output: the objects combined by Merge are either lexical items or sets that were themselves formed by Merge. This recursive property of Merge has been claimed to be a fundamental characteristic that distinguishes language from other cognitive faculties. As Noam Chomsky (1999) puts it, Merge is "an indispensable operation of a recursive system ... which takes two syntactic objects A and B and forms the new object G={A,B}" (p. 2).
In linguistics, Immediate Constituent Analysis (ICA) is a syntactic theory which focuses on the hierarchical structure of sentences by isolating and identifying the constituents. While the idea of breaking down sentences into smaller components can be traced back to early psychological and linguistic theories, ICA as a formal method was developed in the early 20th century. It was influenced by Wilhelm Wundt's psychological theories of sentence structure but was later refined and formalized within the framework of structural linguistics by Leonard Bloomfield. The method gained traction in the distributionalist tradition through the work of Zellig Harris and Charles F. Hockett, who expanded and applied it to sentence analysis. Additionally, ICA was further explored within the context of glossematics by Knud Togeby. These contributions helped ICA become a central tool in syntactic analysis, focusing on the hierarchical relationships between sentence constituents.
In syntax, shifting occurs when two or more constituents appearing on the same side of their common head exchange positions in a sense to obtain non-canonical order. The most widely acknowledged type of shifting is heavy NP shift, but shifting involving a heavy NP is just one manifestation of the shifting mechanism. Shifting occurs in most if not all European languages, and it may in fact be possible in all natural languages including sign languages. Shifting is not inversion, and inversion is not shifting, but the two mechanisms are similar insofar as they are both present in languages like English that have relatively strict word order. The theoretical analysis of shifting varies in part depending on the theory of sentence structure that one adopts. If one assumes relatively flat structures, shifting does not result in a discontinuity. Shifting is often motivated by the relative weight of the constituents involved. The weight of a constituent is determined by a number of factors: e.g., number of words, contrastive focus, and semantic content.
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.
In formal syntax, a node is a point in a tree diagram or syntactic tree that can be assigned a syntactic category label.
