Editing Transformational grammar (section)

==Core concepts==
===Innate linguistic knowledge===
Using a term such as "transformation" may give the impression that theories of transformational generative grammar are intended as a model of the processes by which the human mind constructs and understands sentences, but Chomsky clearly stated that a generative grammar models only the knowledge that underlies the human ability to speak and understand, arguing that because most of that knowledge is innate, a baby can have a large body of knowledge about the structure of language in general and so need to ''learn'' only the idiosyncratic features of the language(s) to which it is exposed.{{Citation needed|date=October 2021}}

Chomsky is not the first person to suggest that all languages have certain fundamental things in common. He quoted philosophers who posited the same basic idea several centuries ago. But Chomsky helped make the innateness theory respectable after a period dominated by more behaviorist attitudes towards language. He made concrete and technically sophisticated proposals about the structure of language as well as important proposals about how grammatical theories' success should be evaluated.<ref>{{cite web |last1=McLeod |first1=S |title=Language Acquisition |url=https://www.simplypsychology.org/language.html |website=Simply Psychology |access-date=21 February 2019}}</ref>

===Grammaticality===
{{Further|Grammaticality}}

Chomsky argued that "grammatical" and "ungrammatical" can be meaningfully and usefully defined. In contrast, an extreme behaviorist linguist would argue that language can be studied only through recordings or transcriptions of actual speech and that the role of the linguist is to look for patterns in such observed speech, not to hypothesize about why such patterns might occur or to label particular utterances grammatical or ungrammatical. Few linguists in the 1950s actually took such an extreme position, but Chomsky was on the opposite extreme, defining grammaticality in an unusually [[mentalism (psychology)|mentalistic]] way for the time.<ref>{{cite book|author=Newmeyer, Frederick J.|title=Linguistic Theory in America|publisher=Academic Press|year=1986|edition=Second}}{{page needed|date=November 2013}}</ref> He argued that the intuition of a [[native speaker]] is enough to define the grammaticality of a sentence; that is, if a particular string of English words elicits a double-take or a feeling of wrongness in a native English speaker, with various extraneous factors affecting intuitions controlled for, it can be said that the string of words is ungrammatical. That, according to Chomsky, is entirely distinct from the question of whether a sentence is meaningful or can be understood. It is possible for a sentence to be both grammatical and meaningless, as in Chomsky's famous example, "[[colorless green ideas sleep furiously]]".<ref>Chomsky 1957:15</ref> But such sentences manifest a linguistic problem that is distinct from that posed by meaningful but ungrammatical (non)-sentences such as "man the bit sandwich the", the meaning of which is fairly clear, but which no [[native speaker]] would accept as well-formed.

===Theory evaluation===
In the 1960s, Chomsky introduced two central ideas relevant to the construction and evaluation of grammatical theories.

==== Competence versus performance ====
One was the distinction between ''[[Linguistic competence|competence]]'' and ''[[Linguistic performance|performance]]''. Chomsky noted that when people speak in the real world, they often make linguistic errors, such as starting a sentence and then abandoning it midway through. He argued that such errors in linguistic ''performance'' are irrelevant to the study of linguistic ''competence'', the knowledge that allows people to construct and understand grammatical sentences. Consequently, the linguist can study an idealised version of language, which greatly simplifies linguistic analysis.

==== Descriptive versus explanatory adequacy ====
The other idea related directly to evaluation of theories of grammar. Chomsky distinguished between grammars that achieve ''descriptive adequacy'' and those that go further and achieve ''explanatory adequacy''. A descriptively adequate grammar for a particular language defines the (infinite) set of grammatical sentences in that language; that is, it describes the language in its entirety. A grammar that achieves explanatory adequacy has the additional property that it gives insight into the mind's underlying linguistic structures. In other words, it does not merely describe the grammar of a language, but makes predictions about how linguistic knowledge is mentally represented. For Chomsky, such mental representations are largely innate and so if a grammatical theory has explanatory adequacy, it must be able to explain different languages' grammatical nuances as relatively minor variations in the universal pattern of human language.

Chomsky argued that even though linguists were still a long way from constructing descriptively adequate grammars, progress in descriptive adequacy would come only if linguists held explanatory adequacy as their goal: real insight into individual languages' structure can be gained only by comparative study of a wide range of languages, on the assumption that they are all cut from the same cloth.{{citation needed|date=November 2013}}