A discussion of syntax would not be complete without looking at one of the most influential theories in linguistics: generative-transformational grammar.
What is generative-transformational grammar?
Introduced in 1957 by Noam Chomsky, his idea of generative-transformational grammar revolutionized the field. Although his current linguistic theories are quite different, we can't talk about linguistics today without looking at Chomsky's generative-transformational grammar. Chomsky's theory offers math-based rules that we can use to visually illustrate how speakers of English -- and all languages -- put sentences together.
Beginning in 1957, Chomsky introduced two central ideas relevant to grammatical theories. The first was the distinction between competence and performance, which we've already looked at in module 1. Central to his theory was explanation of knowledge that underlies the human ability to speak and understand. One of the most important of his ideas is that most of this knowledge is innate, with the result that a baby is born wired to acquire language and needs only actually learn the idiosyncratic features of the language's he or she is exposed to. Perhaps more significantly, he made concrete and technically sophisticated proposals about the structure of language.
The second idea related directly to the evaluation of theories of grammar. Generative transformational grammar tries to explain language creativity: how we are able to utter and interpret sentences we have not heard before. Creativity is made possible by the generative nature of transformational grammar. In order to create and understand newly generated sentences, we must depend on our language competence. Our competence derives from our knowledge of grammar: grammar shapes each of our utterances, setting the boundaries for what is acceptable and ensuring that we will be understood. We compose and structure each of our utterances based on our knowledge of what is acceptable according to the grammatical systems.
What are phrase structure rules?
In generative-transformational grammar theory, phrase structure rules illustrate mathematically our knowledge of how the basic units of a sentence are assembled.
The theory of phrase structure rules states that there is a limited number of rules that are carefully ordered:
According to this theory, you can take a sentence and mathematically divide it into parts.
Chomsky explains that phrase structure rules are are basically "rewriting" rules. For instance, a sentence can be rewritten as a noun phrase plus a verb phrase. In the notation of transformational grammar, this rule is written as:
S --> NP + VP "a sentence consists of a noun phrase followed by a verb phrase"
A sentence can be further illustrated by a phrase structure tree, like this:
Starting with this base, we can begin to build rules which will allow us to generate an infinite number of sentences.
Building a grammar
Our Goal: to build a grammar that generates all of the possible sentences of (English, German, Swahili) and none of the impossible sentences.
Before we begin, we need to recognize that the individual words in a sentence are organized into naturally coherent groups call constituents.
We've already looked at constituents in our activity on identifying subjects and predicates. In these sentences, the subject and predicate are marked:
Seen another way, the constituents in these sentences consist of a noun phrase (NP) and a verb phrase (VP):
The first rule we created above is S --> NP + VP "a sentence consists of a noun phrase + a verb phrase". This rule can be illustrated in this chart:
In the system of rules, S stands for Sentence, NP for Noun Phrase, VP for Verb Phrase, Det for Determiner, Aux for Auxiliary (verb), N for Noun, and V for Verb stem.
Look at the noun phrases in the examples. Some consist of a single noun (John, everyone):
Others consist of an article (a, an) or a determiner (the) plus a noun:
We're beginning to account for creativity and grammaticality judgments.
Let's look at verb phrases in the examples (pasted here again for your convenience):
But the VP rule doesn't explain lay on the table or chased after the children. We need a new VP rule to explain these phrases:
With the rules we have so far...
... we can generate sentences like...
...that we can illustrate in a phrase structure tree like...
... that are explained by these rules:
These phrase structure rules fulfill at least three roles:
Thus phrase structure rules were formulated in order to construct unlimited sentences with a small number of rules.
There is much more to generative-transformational grammar than we've covered in this lesson, including displaying complex sentences and then taking the rules a step further to form another set of rules, called transformational rules, which enable more flexibility and to explain how statements can be transformed into questions or negations. In addition, Noam Chomsky's theories are not without their critics. Still, all linguists owe a debt of thanks to Chomsky for showing us how to illustrate how languages put sentences together.
Ling 102/WI Introduction to the Study of
Language, University of Hawai'i - Leeward Community College
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