Immediate constituent analysis
Encyclopedia
In linguistics, immediate constituent analysis or IC analysis is a method of sentence analysis that was first mentioned by Leonard Bloomfield
and developed further by Rulon Wells. The process reached a full blown strategy for analyzing sentence structure in the early works of Noam Chomsky
. The practice is now widespread. Most tree structures employed to represent the syntactic structure of sentences are products of some form of IC analysis. The process and result of IC analysis can, however, vary greatly based upon whether one chooses a phrase structure grammar
(=constituency grammar) or a dependency grammar
as the underlying relation that organizes constituents
into hierarchical structures.
, IC analysis divides up a sentence into major parts or immediate constituents, and these constituents are in turn divided into further immediate constituents. The process continues until irreducible constituents are reached, i.e., until each constituent consists of only a word or a meaningful part of a word. The end result of IC analysis is often presented in a visual diagrammatic form that reveals the hierarchical immediate constituent structure of a sentence. These diagrams are usually trees
. For example, the sentence
(1) The girl is happy.
can be divided into the immediate constituents The girl and is happy. These in turn can be analyzed into immediate constituents (The+girl) and (is+happy), and so on.
An important aspect of IC analysis in phrase structure grammars is that each individual word is a constituent by definition. The process of IC analysis always ends when the smallest constituents are reached, which are usually words in phrase structure grammars. The process is, however, much different in dependency grammars, since many individual words do not end up as constituents in dependency grammars.
. Since dependency grammars view the finite verb as the root of all sentence structure, they cannot and do not acknowledge the initial subject
-predicate
division of the clause associated with phrase structure grammars. What this means for the general understanding of constituent structure is that dependency grammars do not acknowledge a finite verb phrase
(VP) constituent, and many individual words also do not qualify as constituents, which means in turn that they will not show up as constituents in the IC analysis. Thus in the example sentence The girl is happy, the dependency-based analysis will not view the finite verb phrase is happy, the finite verb
is, or the noun girl as constituents, and these units will not be represented as constituents in the corresponding tree representation.
While the structure that IC analysis identifies for dependency and constituency grammars differ in significant ways, both views of sentence structure are acknowledging constituents. The constituent is defined in a theory-neutral manner:
Constituent
A given word/node plus all the words/nodes that that word/node dominates.
This definition is neutral with respect to the dependency vs. constituency distinction. It allows one to compare the IC analyses across the two types of structure. A constituent is always a complete tree or a complete subtree of a tree, regardless of whether the tree at hand is a constituency or a dependency tree.
. Constituency tests (e.g. topicalization, clefting, pseudoclefting, pro-form substitution, answer fragments, passivization, omission, coordination, etc.) identify the constituents, large and small, of English sentences. Two illustrations of the manner in which constituency tests deliver clues about constituent structure and thus about the correct IC analysis of a given sentence are now given. Consider the constituent The girl in example sentence (1):
(2) a. ...the girl is happy -Topicalization (invalid test because test constituent is already at front of sentence)
Based on these results, one can safely assume that the noun phrase The girl in (1) is a constituent and should therefore be shown as one in the correpsonding IC representation of (1). Consider next what these tests tell us about the verb string is happy:
(3) a. *...is happy, the girl. -Topicalization
The star * indicates that the sentence is bad (i.e. it is not acceptable English). Based on data like (3a-e) we might conclude that the finite verb string is happy in (1) is not a constituent and should therefore not be shown as a constituent in the corresponding IC tree representation of (1).
Leonard Bloomfield
Leonard Bloomfield was an American linguist who led the development of structural linguistics in the United States during the 1930s and the 1940s. His influential textbook Language, published in 1933, presented a comprehensive description of American structural linguistics...
and developed further by Rulon Wells. The process reached a full blown strategy for analyzing sentence structure in the early works of Noam Chomsky
Noam Chomsky
Avram Noam Chomsky is an American linguist, philosopher, cognitive scientist, and activist. He is an Institute Professor and Professor in the Department of Linguistics & Philosophy at MIT, where he has worked for over 50 years. Chomsky has been described as the "father of modern linguistics" and...
. The practice is now widespread. Most tree structures employed to represent the syntactic structure of sentences are products of some form of IC analysis. The process and result of IC analysis can, however, vary greatly based upon whether one chooses a phrase structure grammar
Phrase structure grammar
The term phrase structure grammar was originally introduced by Noam Chomsky as the term for grammars as defined by phrase structure rules, i.e. rewrite rules of the type studied previously by Emil Post and Axel Thue...
(=constituency grammar) or a dependency grammar
Dependency grammar
Dependency grammar is a class of modern syntactic theories that are all based on the dependency relation and that can be traced back primarily to the work of Lucien Tesnière. Dependency grammars are distinct from phrase structure grammars , since they lack phrasal nodes. Structure is determined by...
as the underlying relation that organizes constituents
Constituent (linguistics)
In syntactic analysis, a constituent is a word or a group of words that functions as a single unit within a hierarchical structure. The analysis of constituent structure is associated mainly with phrase structure grammars, although dependency grammars also allow sentence structure to be broken down...
into hierarchical structures.
IC-analysis in phrase structure grammars
Given a phrase structure grammarPhrase structure grammar
The term phrase structure grammar was originally introduced by Noam Chomsky as the term for grammars as defined by phrase structure rules, i.e. rewrite rules of the type studied previously by Emil Post and Axel Thue...
, IC analysis divides up a sentence into major parts or immediate constituents, and these constituents are in turn divided into further immediate constituents. The process continues until irreducible constituents are reached, i.e., until each constituent consists of only a word or a meaningful part of a word. The end result of IC analysis is often presented in a visual diagrammatic form that reveals the hierarchical immediate constituent structure of a sentence. These diagrams are usually trees
Tree (graph theory)
In mathematics, more specifically graph theory, a tree is an undirected graph in which any two vertices are connected by exactly one simple path. In other words, any connected graph without cycles is a tree...
. For example, the sentence
(1) The girl is happy.
can be divided into the immediate constituents The girl and is happy. These in turn can be analyzed into immediate constituents (The+girl) and (is+happy), and so on.
An important aspect of IC analysis in phrase structure grammars is that each individual word is a constituent by definition. The process of IC analysis always ends when the smallest constituents are reached, which are usually words in phrase structure grammars. The process is, however, much different in dependency grammars, since many individual words do not end up as constituents in dependency grammars.
IC analysis in dependency grammars
IC analysis is much different in dependency grammarsDependency grammar
Dependency grammar is a class of modern syntactic theories that are all based on the dependency relation and that can be traced back primarily to the work of Lucien Tesnière. Dependency grammars are distinct from phrase structure grammars , since they lack phrasal nodes. Structure is determined by...
. Since dependency grammars view the finite verb as the root of all sentence structure, they cannot and do not acknowledge the initial subject
Subject (grammar)
The subject is one of the two main constituents of a clause, according to a tradition that can be tracked back to Aristotle and that is associated with phrase structure grammars; the other constituent is the predicate. According to another tradition, i.e...
-predicate
Predicate (grammar)
There are two competing notions of the predicate in theories of grammar. Traditional grammar tends to view a predicate as one of two main parts of a sentence, the other being the subject, which the predicate modifies. The other understanding of predicates is inspired from work in predicate calculus...
division of the clause associated with phrase structure grammars. What this means for the general understanding of constituent structure is that dependency grammars do not acknowledge a finite verb phrase
Verb phrase
In linguistics, a verb phrase or VP is a syntactic unit composed of at least one verb and the dependents of that verb. One can distinguish between two types of VPs, finite VPs and non-finite VPs . While phrase structure grammars acknowledge both, dependency grammars reject the existence of a...
(VP) constituent, and many individual words also do not qualify as constituents, which means in turn that they will not show up as constituents in the IC analysis. Thus in the example sentence The girl is happy, the dependency-based analysis will not view the finite verb phrase is happy, the finite verb
Finite verb
A finite verb is a verb that is inflected for person and for tense according to the rules and categories of the languages in which it occurs. Finite verbs can form independent clauses, which can stand on their own as complete sentences....
is, or the noun girl as constituents, and these units will not be represented as constituents in the corresponding tree representation.
While the structure that IC analysis identifies for dependency and constituency grammars differ in significant ways, both views of sentence structure are acknowledging constituents. The constituent is defined in a theory-neutral manner:
Constituent
A given word/node plus all the words/nodes that that word/node dominates.
This definition is neutral with respect to the dependency vs. constituency distinction. It allows one to compare the IC analyses across the two types of structure. A constituent is always a complete tree or a complete subtree of a tree, regardless of whether the tree at hand is a constituency or a dependency tree.
Constituency tests
The IC analysis for a given sentence is arrived at usually by way of constituency testsConstituent (linguistics)
In syntactic analysis, a constituent is a word or a group of words that functions as a single unit within a hierarchical structure. The analysis of constituent structure is associated mainly with phrase structure grammars, although dependency grammars also allow sentence structure to be broken down...
. Constituency tests (e.g. topicalization, clefting, pseudoclefting, pro-form substitution, answer fragments, passivization, omission, coordination, etc.) identify the constituents, large and small, of English sentences. Two illustrations of the manner in which constituency tests deliver clues about constituent structure and thus about the correct IC analysis of a given sentence are now given. Consider the constituent The girl in example sentence (1):
(2) a. ...the girl is happy -Topicalization (invalid test because test constituent is already at front of sentence)
- b. It is the girl who is happy. -Clefting
- c. (The one)Who is happy is the girl. -Pseudoclefting
- d. She is happy. -Pro-form substitution
- e. Who is happy? -The girl. -Answer fragment
Based on these results, one can safely assume that the noun phrase The girl in (1) is a constituent and should therefore be shown as one in the correpsonding IC representation of (1). Consider next what these tests tell us about the verb string is happy:
(3) a. *...is happy, the girl. -Topicalization
- b. *It is is happy that the girl. -Clefting
- c. *What the girl is is happy. -Pseudoclefting
- d. *The girl so/that/did that. -Pro-form substitution
- e. What is the girl? -*Is happy. -Answer fragment
The star * indicates that the sentence is bad (i.e. it is not acceptable English). Based on data like (3a-e) we might conclude that the finite verb string is happy in (1) is not a constituent and should therefore not be shown as a constituent in the corresponding IC tree representation of (1).
External links
- On the Historical Source of Immediate-Constituent Analysis by W. Keith Percival