Phrase structure rules

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The phrase structure rule is a type of rewrite rule used to describe a particular language syntax and is closely related to the early stages of transformational grammar, first proposed by Noam Chomsky in 1957. They are used to break natural language phrases into its constituent parts, also known as syntactic categories, including lexical categories (parts of speech) and phrasal categories. The grammar that uses the phrase structure rules is a type of phrase structure grammar. The rules of phrase structure as it is commonly used operate according to constituent relations, and the grammar that uses the rules of the expression structure is constituent grammar ; thus, it is very different from dependency grammar , which is based on the dependency relationship.

Video Phrase structure rules

Definisi dan contoh

Aturan struktur frasa biasanya dari bentuk berikut:

${\ displaystyle A \ to B \ quad C}  ÂÂ$

yang berarti bahwa konstituen ${\ displaystyle A}  ÂÂ$ dipisahkan menjadi dua subconstituen ${\ displaystyle B}  ÂÂ$ dan ${\ displaystyle C}  ÂÂ$ . Beberapa contoh untuk bahasa Inggris adalah sebagai berikut:

${\ displaystyle {\ ce {S- & gt; NP \ quad VP}}}  ÂÂ$

${\ displaystyle {\ ce {NP- & gt; (Det) \ quad N1}}}  ÂÂ$

${\ displaystyle {\ ce {N1- & gt; (AP) \ quad N1 \ quad (PP)}}}  ÂÂ$

The first rule reads: A S (sentence) consists of NP (noun phrase) followed by VP (verb phrase). The second rule reads: The noun phrase consists of an optional Det (the determinant) followed by N (noun). The third rule means that N (noun) can be preceded by an optional AP (adjective phrase) and followed by an optional PP (prepositional phrase). Round brackets indicate optional constituents.

Beginning with the symbol of the S sentence, and applying successive phrase structure rules, finally applying the replacement rule to replace the actual words for the abstract symbol, it is possible to generate many appropriate English sentences (or any language defined by the rules). If the rules are correct, then every sentence produced in this way should be grammatically (syntactically) true. It is also hoped that the rule will produce a sentence that is syntactically correct but semantically absurd, like the famous example below:

Dark green idea slept angrily

This phrase was built by Noam Chomsky as an illustration that the phrase structure rules are capable of producing sentences that are syntactically correct but semantically wrong. The phrase structure rules break the sentence into its constituent parts. These constituents are often represented as tree structures (dendrogram). Trees for Chomsky sentences can be given as follows:

A constituent is a word or combination of words dominated by a single node. So each word is a constituent. Furthermore, subject NP Green colorless ideas , NP minor green ideas , and VP sleeping angrily are constituents. The rules of phrase structure and tree structure associated with it are forms of direct constituent analysis.

In transformational grammar, the phrase structure rule system is equipped with transformation rules, which act on existing syntactic structures to produce new ones (perform operations such as negation, pacifism, etc.). This transformation is not really necessary for generations, because the phrases they produce can be produced by the appropriate phrase structure expression system only, but the transformation provides a larger economy and allows a significant relationship between sentences to be reflected in the grammar.

Maps Phrase structure rules

Top down

One important aspect of the phrase structure rule is that they see the sentence structure from top to bottom. The category to the left of the arrow is the larger constituent and the immediate constituent to the right of the arrow is the lower constituent. Constituents are successively broken up into their parts as one moves down the list of phrase structure rules for a given sentence. This top-down view of this sentence structure is in stark contrast to much of the work done in modern theoretical syntax. In Minimalism for example, sentence structure is generated from bottom to top. Merging operations combine smaller constituents to create larger constituencies until the largest constituents (ie sentences) are reached. In this case, theoretical syntax ignores the old phrase structure rules, although their interests for computational linguistics seem to remain intact.

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Alternate approach

Constituency vs. dependency

The phrase structure rules as commonly used result in the appearance of sentence structures that are constituent based . Thus, the grammar using the phrase structure rule is constituent grammar (= grammar of the structure phrase), as opposed to grammatical dependence , which looks at the sentence structure as dependency based . What this means is that for the phrase structure rules can be applied at all, we must pursue an understanding based on the constituent sentence structure. The constituent relation is a one-to-one-or-more correspondence. For each word in a sentence, there is at least one node in the syntactic structure corresponding to that word. The dependency relation, on the other hand, is a one-to-one relationship; for every word in a sentence, there is exactly one node in the syntactic structure corresponding to that word. The difference is illustrated by the following trees:

The constituent tree on the left can be generated by the rules of the phrase structure. Sentence S is broken down into smaller and smaller constituent parts. The dependency tree on the right can not, by contrast, be generated by the rules of the phrase structure (at least not as it is usually interpreted).

Grammar representative

A number of theories of sentence representational structure of grammar never recognize the rules of phrase structure, but rather pursue the understanding of sentence structure in terms of the concept of schema. Here the phrase structure does not come from rules that combine words, but from the specification or instantiation of the syntactic schema or configuration, often expressing some kind of semantic content regardless of the specific words that appear in it. This approach is essentially equivalent to the phrase structure rule system combined with the noncomposition semantic theory, since grammatical formalism based on the rewrite rule is generally equivalent to the power to be based on substitution into the schemata.

So in this type of approach, instead of being derived from the implementation of a number of phrase structure rules, the phrase green ideas without sleeping with angry colors will be generated by filling in the words into the schematic slots that have the following structure:

[NP [ADJ N] VP [V] AP [[ADV]]

And that will reveal the following conceptual content:

X DOES Y IN MANNER OF Z

Although they are noncompositional, such models are monotonous. This approach is highly evolved in Construction grammar and has had an influence in Grammar Head-Driven Procedures and Lexical Functional Grammar, the latter two clearly qualify as grammatical phrase structures.

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See also

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Note

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References

Source of the article : Wikipedia