Center embedding
Encyclopedia
In linguistics
, center embedding refers to the process of embedding a phrase
in the middle of another phrase of the same type. This often leads to difficulty with parsing
which would be difficult to explain on grammatical grounds alone. The most frequently used example involves embedding a relative clause
inside another one as in:
In theories of natural language parsing, the difficulty with multiple center embedding is thought to arise from limitations of the human short term memory. In order to process multiple center embeddings, we have to store many subjects in order to connect them to their predicate
s.
An interesting theoretical point is that sentences with multiple center embedding are grammatical
, but unacceptable. Such examples are behind Noam Chomsky
's comment that, “Languages are not 'designed for parsability' ... we may say that languages, as such, are not usable.” (Chomsky, 1991)
Some researchers (such as Peter Reich) came up with theories that though single center embedding is acceptable (as in "the man that boy kicked is a friend of mine"), double center embedding is not. The linguist Anne De Roeck and colleagues provided a counter-example: "Isn't it true that example-sentences that people that you know produce are more likely to be accepted?" (De Roeck et al., 1982).
The linguist Fred Karlsson
provided empirical evidence in 2007 that the maximal degree of multiple center-embedding of clauses is exactly 3 in written language. He provided thirteen genuine examples of this type from various Indo-European languages (Danish, English, German, Latin, Swedish). No real examples of degree 4 have been recorded. In spoken language, multiple center-embeddings even of degree 2 are so rare as to be practically non-existing (Karlsson 2007).
Unusually for an obscure aspect of grammar
, center embedding is the focus of a science fiction
novel, Ian Watson
's The Embedding, and plays a part in Ted Chiang
's Story of Your Life
.
Linguistics
Linguistics is the scientific study of human language. Linguistics can be broadly broken into three categories or subfields of study: language form, language meaning, and language in context....
, center embedding refers to the process of embedding a phrase
Phrase
In everyday speech, a phrase may refer to any group of words. In linguistics, a phrase is a group of words which form a constituent and so function as a single unit in the syntax of a sentence. A phrase is lower on the grammatical hierarchy than a clause....
in the middle of another phrase of the same type. This often leads to difficulty with parsing
Parsing
In computer science and linguistics, parsing, or, more formally, syntactic analysis, is the process of analyzing a text, made of a sequence of tokens , to determine its grammatical structure with respect to a given formal grammar...
which would be difficult to explain on grammatical grounds alone. The most frequently used example involves embedding a relative clause
Relative clause
A relative clause is a subordinate clause that modifies a noun phrase, most commonly a noun. For example, the phrase "the man who wasn't there" contains the noun man, which is modified by the relative clause who wasn't there...
inside another one as in:
- A man that a woman loves
- A man that a woman that a child knows loves
- A man that a woman that a child that a bird saw knows loves
- A man that a woman that a child that a bird that I heard saw knows loves
In theories of natural language parsing, the difficulty with multiple center embedding is thought to arise from limitations of the human short term memory. In order to process multiple center embeddings, we have to store many subjects in order to connect them to their 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...
s.
An interesting theoretical point is that sentences with multiple center embedding are grammatical
Grammaticality
In theoretical linguistics, grammaticality is the quality of a linguistic utterance of being grammatically well-formed. An * before a form is a mark that the cited form is ungrammatical....
, but unacceptable. Such examples are behind 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...
's comment that, “Languages are not 'designed for parsability' ... we may say that languages, as such, are not usable.” (Chomsky, 1991)
Some researchers (such as Peter Reich) came up with theories that though single center embedding is acceptable (as in "the man that boy kicked is a friend of mine"), double center embedding is not. The linguist Anne De Roeck and colleagues provided a counter-example: "Isn't it true that example-sentences that people that you know produce are more likely to be accepted?" (De Roeck et al., 1982).
The linguist Fred Karlsson
Fred Karlsson
Fred Karlsson is a professor of general linguistics at the University of Helsinki.In computational linguistics Karlsson has designed a language-independent formalism called Constraint Grammar...
provided empirical evidence in 2007 that the maximal degree of multiple center-embedding of clauses is exactly 3 in written language. He provided thirteen genuine examples of this type from various Indo-European languages (Danish, English, German, Latin, Swedish). No real examples of degree 4 have been recorded. In spoken language, multiple center-embeddings even of degree 2 are so rare as to be practically non-existing (Karlsson 2007).
Unusually for an obscure aspect of grammar
Grammar
In linguistics, grammar is the set of structural rules that govern the composition of clauses, phrases, and words in any given natural language. The term refers also to the study of such rules, and this field includes morphology, syntax, and phonology, often complemented by phonetics, semantics,...
, center embedding is the focus of a science fiction
Science fiction
Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
novel, Ian Watson
Ian Watson (author)
Ian Watson is a British science fiction author. He currently lives in Northamptonshire, England.His first novel, The Embedding, winner of the Prix Apollo in 1975, is unusual for being based on ideas from generative grammar; the title refers to the process of center embedding...
's The Embedding, and plays a part in Ted Chiang
Ted Chiang
Ted Chiang is an American speculative fiction writer. His Chinese name is Chiang Feng-nan.He was born in Port Jefferson, New York and graduated from Brown University with a Computer Science degree. He currently works as a technical writer in the software industry and resides in Bellevue, near...
's Story of Your Life
Story of Your Life
Story of Your Life is a science fiction short story by Ted Chiang. It was the winner of the 2000 Nebula Award for Best Novella as well as the 1999 Sturgeon award. The major themes explored by this tale are determinism, language, and an interesting take on the Sapir–Whorf hypothesis.-Plot summary:Dr...
.
External links
- New speech disorder linguists contracted discovered!: A humorous example of excessive center embedding. The general gist is quite understandable, but the details of the relationships are hard to manage.