In
linguistics
Linguistics is the scientific study of human language. It is called a scientific study because it entails a comprehensive, systematic, objective, and precise analysis of all aspects of language, particularly its nature and structure. Linguis ...
, X-bar theory is a model of phrase-structure grammar and a theory of syntactic category formation that was first proposed by
Noam Chomsky
Avram Noam Chomsky (born December 7, 1928) is an American public intellectual: a linguist, philosopher, cognitive scientist, historian, social critic, and political activist. Sometimes called "the father of modern linguistics", Chomsky is ...
in 1970
[Chomsky, Noam (1970). Remarks on Nominalization. In: R. Jacobs and P. Rosenbaum (eds.) ''Reading in English Transformational Grammar'', 184–221. Waltham: Ginn.] and further developed by
Ray Jackendoff
Ray Jackendoff (born January 23, 1945) is an American linguist. He is professor of philosophy, Seth Merrin Chair in the Humanities and, with Daniel Dennett, co-director of the Center for Cognitive Studies at Tufts University. He has always str ...
(1974,
1977a,
1977b
[Jackendoff, Ray (1977b) Constraints on Phrase Structure Rules, in P. W. Culicover, T. Wasow & A. Akmajian (eds.), ''Formal Syntax'', Academic Press, New York, pp. 249–83.]), along the lines of the theory of
generative grammar
Generative grammar, or generativism , is a linguistic theory that regards linguistics as the study of a hypothesised innate grammatical structure. It is a biological or biologistic modification of earlier structuralist theories of linguistic ...
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
In neuropsychology, linguistics, and philosophy of language, a natural language or ordinary language is any language that has evolved naturally in humans through use and repetition without conscious planning or premeditation. Natural languages ...
is an XP (X phrase) that is headed by a given
syntactic category A syntactic category is a syntactic unit that theories of syntax assume. Word classes, largely corresponding to traditional parts of speech (e.g. noun, verb, preposition, etc.), are syntactic categories. In phrase structure grammars, the ''phrasal c ...
X. It played a significant role in resolving issues that
phrase structure rules
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 lang ...
had, representative of which is the proliferation of grammatical rules, which is against the thesis of generative grammar.
X-bar theory was incorporated into both transformational and nontransformational theories of syntax, including
government and binding theory
A government is the system or group of people governing an organized community, generally a state.
In the case of its broad associative definition, government normally consists of legislature, executive, and judiciary. Government is a ...
(GB),
generalized phrase structure grammar Generalized phrase structure grammar (GPSG) is a framework for describing the syntax and semantics of natural languages. It is a type of constraint-based phrase structure grammar. Constraint based grammars are based around defining certain syntacti ...
(GPSG),
lexical-functional grammar (LFG), and
head-driven phrase structure grammar Head-driven phrase structure grammar (HPSG) is a highly lexicalized, constraint-based grammar
developed by Carl Pollard and Ivan Sag. It is a type of phrase structure grammar, as opposed to a dependency grammar, and it is the immediate successor to ...
(HPSG). Although recent work in the
minimalist program
In linguistics, the minimalist program is a major line of inquiry that has been developing inside generative grammar since the early 1990s, starting with a 1993 paper by Noam Chomsky.
Following Imre Lakatos's distinction, Chomsky presents minima ...
has largely abandoned X-bar schemata in favor of
bare phrase structure
In linguistics, the minimalist program is a major line of inquiry that has been developing inside generative grammar since the early 1990s, starting with a 1993 paper by Noam Chomsky.
Following Imre Lakatos's distinction, Chomsky presents minima ...
approaches, the theory's central assumptions are still valid in different forms and terms in many theories of minimalist syntax.
Background
The X-bar theory was developed to resolve the issues that
phrase structure rules
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 lang ...
(PSR) under the
Standard Theory[.] had.
The PSR approach has the following four main issues.
# It assumes
exocentric structure
In theoretical linguistics, a distinction is made between endocentric and exocentric constructions. A grammatical construction (for instance, a phrase or compound) is said to be ''endocentric'' if it fulfils the same linguistic function as one of ...
s
[Phrasal structures that lack a ]head
A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...
. such as "S → NP Aux VP". This is contrary to the fact that
phrases
In syntax and grammar, a phrase 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 consi ...
have
heads
A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may no ...
in all circumstances.
# While the sentence ''John talked to the man'', for example, involves the PSR of a
verb phrase
In linguistics, a verb phrase (VP) is a syntactic unit composed of a verb and its arguments except the subject of an independent clause or coordinate clause. Thus, in the sentence ''A fat man quickly put the money into the box'', the words ''quic ...
"VP → V (PP)",
[The parentheses indicate that the phrasal category in them is optional.] ''John talked to the man in person'' involves the PSR of "VP → V (PP) (PP)". This indicates that it is necessary to posit new PSRs every time when an undefined structure is observed in
E-language
In linguistics, transformational grammar (TG) or transformational-generative grammar (TGG) is part of the theory of generative grammar, especially of natural languages. It considers grammar to be a system of rules that generate exactly those comb ...
, which amounts to adding an indiscriminate number of grammatical rules to
Universal Grammar
Universal grammar (UG), in modern linguistics, is the theory of the genetic component of the language faculty, usually credited to Noam Chomsky. The basic postulate of UG is that there are innate constraints on what the grammar of a possible hum ...
. This poses serious issues from the perspectives of the
Plato's problem and the
poverty of the stimulus
Poverty of the stimulus (POS) is the controversial argument from linguistics that children are not exposed to rich enough data within their linguistic environments to acquire every feature of their language. This is considered evidence contrary to ...
.
# It wrongly rules in structures that are impossible in
natural language
In neuropsychology, linguistics, and philosophy of language, a natural language or ordinary language is any language that has evolved naturally in humans through use and repetition without conscious planning or premeditation. Natural languages ...
such as "VP → NP A PP", because as in 1 and 2, the PSR countenances phrases that do not have
endocentric structure
In theoretical linguistics, a distinction is made between endocentric and exocentric constructions. A grammatical construction (for instance, a phrase or compound) is said to be ''endocentric'' if it fulfils the same linguistic function as one of ...
s.
[Phrasal structures that include a ]head
A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...
.
# It fails to capture sentence ambiguities because it assumes flat, nonhierarchical structures.
The X-bar theory is a theory that attempts to resolve these issues by assuming the mold or template phrasal structure of "XP".
X-bar schema
Basic principles
The "X" in the X-bar theory is equivalent to a
variable
Variable may refer to:
* Variable (computer science), a symbolic name associated with a value and whose associated value may be changed
* Variable (mathematics), a symbol that represents a quantity in a mathematical expression, as used in many ...
in mathematics: It can be substituted by
syntactic categories A syntactic category is a syntactic unit that theories of syntax assume. Word classes, largely corresponding to traditional parts of speech (e.g. noun, verb, preposition, etc.), are syntactic categories. In phrase structure grammars, the ''phrasal c ...
such as
N,
V,
A, and
P. These categories are
lexemes
A lexeme () is a unit of lexical meaning that underlies a set of words that are related through inflection. It is a basic abstract unit of meaning, a unit of morphological analysis in linguistics that roughly corresponds to a set of forms taken ...
and not
phrases
In syntax and grammar, a phrase 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 consi ...
: The "X-bar" is a grammatical unit larger than X, thus than a lexeme, and the X-double-bar (=XP) outsizes the X(-single)-bar. X-double-bar categories are equal to
phrasal categories such as
NP,
VP,
AP, and
PP.
The X-bar theory assumes that all
phrasal categories have the structure in Figure 1.
This structure is called the X-bar schema.
![X-bar_schema_(basic)](https://upload.wikimedia.org/wikipedia/commons/3/38/X-bar_schema_%28basic%29.png)
As in Figure 1, the phrasal category XP is notated by an X with a double overbar. For typewriting reasons, the bar symbol is often substituted by the prime ('), as in X'.
The X-bar theory embodies two central principles.
* Headedness principle: Every phrase has a head.
* Binarity principle: Every
node
In general, a node is a localized swelling (a "knot") or a point of intersection (a vertex).
Node may refer to:
In mathematics
*Vertex (graph theory), a vertex in a mathematical graph
*Vertex (geometry), a point where two or more curves, lines, ...
branches into two different nodes.
The headedness principle resolves the issues 1 and 3 above simultaneously. The binarity principle is important to projection and ambiguity, which will be explained below.
The X-bar schema consists of a head and its circumstantial components, in accordance with the headedness principle.
The relevant components are as follows:
* Specifier:
obligatory">/nowiki>obligatory/nowiki> The node that is in a sister relation with an X' node. This is a term that refers to the syntactic position itself.
* Head
A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...
: obligatory">/nowiki>obligatory/nowiki> The core of a phrase, into which a lexeme
A lexeme () is a unit of lexical meaning that underlies a set of words that are related through inflection. It is a basic abstract unit of meaning, a unit of morphological analysis in linguistics that roughly corresponds to a set of forms taken ...
fits. The head determines the form and characteristics of the phrase as a whole.
* Complement
A complement is something that completes something else.
Complement may refer specifically to:
The arts
* Complement (music), an interval that, when added to another, spans an octave
** Aggregate complementation, the separation of pitch-class ...
: obligatory">/nowiki>obligatory/nowiki> An argument
An argument is a statement or group of statements called premises intended to determine the degree of truth or acceptability of another statement called conclusion. Arguments can be studied from three main perspectives: the logical, the dialectic ...
required by the head.
* Adjunct: optional">/nowiki>optional/nowiki> A modifier for the phrase constituted by the head.
The specifier, head, and complement are obligatory; hence, a phrasal category XP must contain one specifier, one head, and one complement. On the other hand, the adjunct is optional; hence, a phrasal category contains zero or more adjuncts. Accordingly, when a phrasal category XP does not have an adjunct, it forms the structure in Figure 2.
For example, the NP ''linguistics'' in the sentence ''John studies linguistics'' has the structure in Figure 3.
It is important that even if there are no candidates that can fit into the specifier and complement positions, these positions are syntactically present, and thus they are merely empty and unoccupied. (This is a natural consequence of the binarity principle.) This means that all phrasal categories have fundamentally uniform structures under the X-bar schema, which makes it unnecessary to assume that different phrases have different structures, unlike when we adopt the PSR. (This resolves the second issue above.) In the meanwhile, one needs to be wary of when such empty positions are representationally omitted as in Figure 4.
In illustrating syntactic structures this way, at least one X'-level node
In general, a node is a localized swelling (a "knot") or a point of intersection (a vertex).
Node may refer to:
In mathematics
*Vertex (graph theory), a vertex in a mathematical graph
*Vertex (geometry), a point where two or more curves, lines, ...
is present in any circumstance because the complement is obligatory.
Next, the X'' and X' inherit the characteristics of the head X. This trait inheritance is referred to as ''projection''.
Figure 5 suggests that syntactic structures are derived in a bottom-up fashion under the X-bar theory. More specifically, the structures are derived via the following processes.
# A lexeme is fitted into the head. Note that heads are sometimes called ''zero-level projections'' because they are X-zero-bar-level categories, notated as X0.
# The head and the complement are combined to form an X-single-bar (X, X') node, which constitutes a semi-phrasal category (a syntactic category not as big as a phrase). This category is called ''intermediate projection''.
# (An adjunct, if there is any, combines with an X' to form another X'. If there is more than one adjunct, this process is repeated.)
# An intermediate projection combines with the specifier, forming a complete phrasal category XP (X-double-bar). This category is called ''maximal projection''.
It is important that all the processes except for the third are obligatory. This means that one phrasal category necessarily includes X0, X, and XP (=X''). Moreover, nodes
In general, a node is a localized swelling (a "knot") or a point of intersection (a Vertex (graph theory), vertex).
Node may refer to:
In mathematics
*Vertex (graph theory), a vertex in a mathematical graph
*Vertex (geometry), a point where two ...
bigger than X0 (thus, X and XP nodes) are called constituents.
Directionality of branching
Figures 1–5 are based on the word order
In linguistics, word order (also known as linear order) is the order of the syntactic constituents of a language. Word order typology studies it from a cross-linguistic perspective, and examines how different languages employ different orders. C ...
of English
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ''English'', an adjective for something of, from, or related to England
** English national ide ...
, but the X-bar schema does not specify the directionality of branching because the binarity principle does not have a rule on it. For example, ''John read a long book of linguistics with a red cover'', which involves two adjuncts, may have either of the structures in Figure 6 or Figure 7. (The figures follow the convention of omitting the inner structures of certain phrasal categories with triangles.)
The structure in Figure 6 yields the meaning ''the book of linguistics with a red cover is long'', and the one in Figure 7 ''the long book of linguistics is with a red cover'' (see also #Hierarchical structure). What is important is the directionality of the nodes N'2 and N'3: One is left-branching, while the other is right-branching. Accordingly, the X-bar theory, more specifically the binarity principle, does not impose a restriction on how a node branches.
When it comes to the head and the complement, their relative order is determined based on the principles-and-parameters model of language, more specifically by the head parameter
In linguistics, head directionality is a proposed Principles and parameters, parameter that classifies languages according to whether they are head-initial (the head (linguistics), head of a phrase precedes its Complement (linguistics), complem ...
(not by the X-bar schema itself). A principle
A principle is a proposition or value that is a guide for behavior or evaluation. In law, it is a Legal rule, rule that has to be or usually is to be followed. It can be desirably followed, or it can be an inevitable consequence of something, suc ...
is a shared, invariable rule of grammar across languages, whereas a parameter
A parameter (), generally, is any characteristic that can help in defining or classifying a particular system (meaning an event, project, object, situation, etc.). That is, a parameter is an element of a system that is useful, or critical, when ...
is a typologically variable aspect of the grammars. One can either set their parameter with the values of "+" or "-": In the case of the head parameter, one configures the parameter of head first/nowiki>, depending on what language they primarily speak. If this parameter is configured to be head first
Head First or Headfirst may refer to:
Music
* ''Head First'' (The Babys album) (1979)
* ''Head First'' (Badfinger album) (recorded 1974, released 2000)
* ''Head First'' (Goldfrapp album) (2010), or its title track
* ''Head First'' (Uriah Hee ...
/nowiki>, what results is head-initial languages such as English, and if it is configured to be head first
Head First or Headfirst may refer to:
Music
* ''Head First'' (The Babys album) (1979)
* ''Head First'' (Badfinger album) (recorded 1974, released 2000)
* ''Head First'' (Goldfrapp album) (2010), or its title track
* ''Head First'' (Uriah Hee ...
/nowiki>, what results is head-final languages such as Japanese
Japanese may refer to:
* Something from or related to Japan, an island country in East Asia
* Japanese language, spoken mainly in Japan
* Japanese people, the ethnic group that identifies with Japan through ancestry or culture
** Japanese diaspor ...
. For example, the English sentence ''John ate an apple'' and its corresponding Japanese sentence ''John-ga ringo-o tabe-ta'' (ジョンがリンゴを食べた; John-NOM apple-ACC eat-PAST) have the structures in Figure 8 and Figure 9, respectively.
Note finally that the directionality of the specifier node is in essence unspecified as well, although this is subject to debate: Some argue that the relevant node is necessarily left-branching across languages, the idea of which is (partially) motivated by the fact that both English and Japanese have subjects on the left of a VP, whereas others such as Saito and Fukui (1998) argue that the directionality of the node is not fixed and needs to be externally determined, for example by the head parameter.
Structure of sentence
Structure of S
Under the PSR, the structure of S (sentence) is illustrated as follows.
* S → NP (Aux) VP
However, this structure violates the headedness principle because it has an exocentric, headless structure, and would also violate the binarity principle if an Aux (auxiliary) occurs, because the S node will then be ternary-branching. Given these, Chomsky (1981) proposed that S is an InflP headed by the functional category Infl(ection), and later in Chomsky (1986a), this category was relabelled as I (hence constitutes an IP), following the notational convention that phrasal categories are represented in the form of XP, with two letters. The category I includes auxiliary verbs such as ''will'' and ''can'', clitics such as ''-s'' of the third person singular present and ''-ed'' of the past tense. This is consistent with the headedness principle, which requires that a phrase have a head, because a sentence (or a clause) necessarily involves an element that determines the inflection of a verb.
Assuming that S constitutes an IP, the structure of the sentence ''John studies linguistics at the university'', for example, can be illustrated as in Figure 10.
As is obvious, the IP hypothesis makes it possible to regard the grammatical unit of sentence as a phrasal category. It is also important that the configuration in Figure 10 is fully compatible with the central assumptions of the X-bar theory, namely the headedness principle and the binarity principle.
Structure of S'
Words that introduce subordinate
A hierarchy (from Greek: , from , 'president of sacred rites') is an arrangement of items (objects, names, values, categories, etc.) that are represented as being "above", "below", or "at the same level as" one another. Hierarchy is an important ...
or complement clauses are called complementizer
In linguistics (especially generative grammar), complementizer or complementiser (glossing abbreviation: ) is a functional category (part of speech) that includes those words that can be used to turn a clause into the subject or object of a s ...
s, and representative of them are ''that'', ''if'', and ''for.'' Under the PSR, complement clauses were assumed to constitute the category S'.[Bresnan, Joan (1972) ''Theory of Complementation in English Syntax'', Doctoral dissertation, MIT.]
* S' → COMP S
Chomsky (1986a) proposed that this category is in fact a CP headed by the functional category C. The sentence ''I think that John is honest'', for example, then has the following structure.
Moreover, Chomsky (1986a) assumes that the landing site of wh-movement
In linguistics, wh-movement (also known as wh-fronting, wh-extraction, or wh-raising) is the formation of syntactic dependencies involving interrogative words. An example in English is the dependency formed between ''what'' and the object position ...
is the specifier position of CP (Spec-CP). Accordingly, the wh-question
A question is an utterance which serves as a request for information. Questions are sometimes distinguished from interrogatives, which are the grammatical forms typically used to express them. Rhetorical questions, for instance, are interrogative ...
''What did John eat?'', for example, is derived as in Figure 12.
In this derivation, the I-to-C movement is an instance of subject-auxiliary inversion (SAI), or more generally, head movement
Syntactic 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 constituen ...
.
Other phrasal structures
* VP-internal subject hypothesis: A hypothesis on the inner structure of VP proposed by researchers such as Fukui and Speas (1986) and Kitagawa (1986). It assumes that the sentential subject is base-generated in Spec-VP, not in Spec-IP.
* DP Hypothesis: A hypothesis proposed by Abney (1987), according to whom noun phrases are not NPs but DPs headed by the functional category D.
* VP shell: An analysis put forth by Larson (1988), which assumes two-layered structures of VP. Later in Chomsky (1995), the higher VP was replaced by ''v''P headed by the functional category ''v'' (little/small v, traditionally written in italics).
* PredP Hypothesis: A hypothesis proposed by Bowers (1993, 2001), according to whom small clause In linguistics, a small clause consists of a subject and its predicate, but lacks an overt expression of tense. Small clauses have the semantic subject-predicate characteristics of a clause, and have some, but not all, the properties of a constitue ...
s[Stowell, Timothy (1981). ''Origins of Phrase Structure''. Doctoral dissertation, MIT.] are PredPs headed by the functional category Pred.
* Bare Phrase Structure
In linguistics, the minimalist program is a major line of inquiry that has been developing inside generative grammar since the early 1990s, starting with a 1993 paper by Noam Chomsky.
Following Imre Lakatos's distinction, Chomsky presents minima ...
(BPS): A theory put forth by Chomsky (1995) as a replacement of the X-bar theory. It dispenses with a "template" structure like the X-bar schema, and yields syntactic structures by (iterative applications of) an operation called Merge
Merge, merging, or merger may refer to:
Concepts
* Merge (traffic), the reduction of the number of lanes on a road
* Merge (linguistics), a basic syntactic operation in generative syntax in the Minimalist Program
* Merger (politics), the comb ...
, which serves to connect two syntactic objects such as words and phrases into one. Some radical versions of it even reject syntactic category labels such as V and A. See also Minimalist Program
In linguistics, the minimalist program is a major line of inquiry that has been developing inside generative grammar since the early 1990s, starting with a 1993 paper by Noam Chomsky.
Following Imre Lakatos's distinction, Chomsky presents minima ...
.
Hierarchical structure
The PSR has the shortcoming of being incapable of capturing sentence ambiguities.
* I saw a man with binoculars.
This sentence is ambiguous between the reading ''I saw a man, using binoculars'', in which ''with binoculars'' modifies the VP, and the reading ''I saw a man who had binoculars'', in which the PP modifies the NP. Under the PSR model, the sentence above is subject to the following two parsing rules.
* S → NP VP
* VP → V NP PP
The sentence's structure under these PSRs would be as in Figure 13.
It is obvious that this structure fails to capture the NP modification reading because PP with binoculars">sub>PP with binocularsmodifies the VP no matter how one tries to illustrate the structure. The X-bar theory, however, successfully captures the ambiguity as demonstrated in the configurations in Figure 14 and 15 below, because it assumes hierarchical structures in accordance with the binarity principle.
Thus, the X-bar theory resolves the fourth issue mentioned in #Background as well. Note that there is always a unilateral relation from syntax to semantics (never from semantics to syntax) in any version of generative grammar
Generative grammar, or generativism , is a linguistic theory that regards linguistics as the study of a hypothesised innate grammatical structure. It is a biological or biologistic modification of earlier structuralist theories of linguistic ...
because syntactic computation starts from the lexicon
A lexicon is the vocabulary of a language or branch of knowledge (such as nautical or medical). In linguistics, a lexicon is a language's inventory of lexemes. The word ''lexicon'' derives from Koine Greek language, Greek word (), neuter of () ...
, then continues into the syntax, then into Logical Form
In logic, logical form of a statement is a precisely-specified semantic version of that statement in a formal system. Informally, the logical form attempts to formalize a possibly ambiguous statement into a statement with a precise, unambiguo ...
(LF) at which meanings are computed. This is so under any of Standard Theory (Chomsky 1965), Extended Standard Theory (Chomsky 1972), and Revised Extended Standard Theory
Generative grammar, or generativism , is a linguistic theory that regards linguistics as the study of a hypothesised innate grammatical structure. It is a biological or biologistic modification of earlier structuralist theories of linguistic ...
(Chomsky 1981).
Footnotes
References
See also
* Linguistics
Linguistics is the scientific study of human language. It is called a scientific study because it entails a comprehensive, systematic, objective, and precise analysis of all aspects of language, particularly its nature and structure. Linguis ...
* Natural language
In neuropsychology, linguistics, and philosophy of language, a natural language or ordinary language is any language that has evolved naturally in humans through use and repetition without conscious planning or premeditation. Natural languages ...
* Syntax
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) ...
* Constituent (linguistics)
In syntactic analysis, a constituent is a word or a group of words that function as a single unit within a hierarchical structure. The constituent structure of sentences is identified using ''tests for constituents''. These tests apply to a portio ...
* Parse tree
A parse tree or parsing tree or derivation tree or concrete syntax 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 co ...
* Head (linguistics)
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 ste ...
* Complement (linguistics)
In grammar, a complement is a word, phrase, or clause that is necessary to complete the meaning of a given expression. Complements are often also arguments (expressions that help complete the meaning of a predicate).
Predicative, subject and o ...
* Phrase
In syntax and grammar, a phrase 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 consi ...
* Syntactic category A syntactic category is a syntactic unit that theories of syntax assume. Word classes, largely corresponding to traditional parts of speech (e.g. noun, verb, preposition, etc.), are syntactic categories. In phrase structure grammars, the ''phrasal c ...
* Lexical category
* Functional category
* Part of speech
In grammar, a part of speech or part-of-speech (abbreviated as POS or PoS, also known as word class or grammatical category) is a category of words (or, more generally, of lexical items) that have similar grammatical properties. Words that are assi ...
* Node (linguistics)
* Generative grammar
Generative grammar, or generativism , is a linguistic theory that regards linguistics as the study of a hypothesised innate grammatical structure. It is a biological or biologistic modification of earlier structuralist theories of linguistic ...
* Universal Grammar
Universal grammar (UG), in modern linguistics, is the theory of the genetic component of the language faculty, usually credited to Noam Chomsky. The basic postulate of UG is that there are innate constraints on what the grammar of a possible hum ...
* Plato's problem
* Poverty of the stimulus
Poverty of the stimulus (POS) is the controversial argument from linguistics that children are not exposed to rich enough data within their linguistic environments to acquire every feature of their language. This is considered evidence contrary to ...
* Transformational grammar
In linguistics, transformational grammar (TG) or transformational-generative grammar (TGG) is part of the theory of generative grammar, especially of natural languages. It considers grammar to be a system of rules that generate exactly those combin ...
* Phrase structure grammar
The term phrase structure grammar was originally introduced by Noam Chomsky as the term for grammar studied previously by Emil Post and Axel Thue (Post canonical systems). Some authors, however, reserve the term for more restricted grammars in the ...
* Phrase structure rule
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 lang ...
* Standard Theory
* Extended Standard Theory
* Revised Extended Standard Theory
Generative grammar, or generativism , is a linguistic theory that regards linguistics as the study of a hypothesised innate grammatical structure. It is a biological or biologistic modification of earlier structuralist theories of linguistic ...
* Government and binding theory
A government is the system or group of people governing an organized community, generally a state.
In the case of its broad associative definition, government normally consists of legislature, executive, and judiciary. Government is a ...
* C-command
In generative grammar and related frameworks, a node in a parse tree c-commands its sister node and all of its sister's descendants. In these frameworks, c-command plays a central role in defining and constraining operations such as syntactic mov ...
* Principles-and-parameters approach
* Minimalist Program
In linguistics, the minimalist program is a major line of inquiry that has been developing inside generative grammar since the early 1990s, starting with a 1993 paper by Noam Chomsky.
Following Imre Lakatos's distinction, Chomsky presents minima ...
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