Grammaticality


In linguistics, grammaticality is conformity to grammar. The notion of grammaticality rose alongside the theory of generative grammar, the goal of which is to formulate rules that define well-formed, grammatical sentences. These rules of grammaticality also provide explanations of ill-formed, ungrammatical sentences.
In theoretical linguistics, a speaker's judgement on the well-formedness of a linguistic 'string'—called a grammaticality judgement—is based on whether the sentence is interpreted in accordance with the rules and constraints of the relevant grammar. If the rules and constraints of the particular lect are followed, then the sentence is judged to be grammatical. In contrast, an ungrammatical sentence is one that violates the rules of the given language variety.
Linguists use grammaticality judgements to investigate the syntactic structure of sentences. Generative linguists are largely of the opinion that for native speakers of natural languages, grammaticality is a matter of linguistic intuition, and reflects the innate linguistic competence of speakers. Therefore, generative linguists attempt to predict grammaticality judgements exhaustively.
Grammaticality judgements are largely based on an individual's linguistic intuition, and it has been pointed out that humans have the ability to understand as well as produce an infinitely large number of new sentences that have never been seen before. This allows us to accurately judge a sentence as grammatical or ungrammatical, even if it is a completely novel sentence.

Background

Criteria that determine grammaticality

According to Chomsky, a speaker's grammaticality judgement is based on two factors:
  1. A native speaker's linguistic competence, which is the knowledge that they have of their language, allows them to easily judge whether a sentence is grammatical or ungrammatical based on intuitive introspection. For this reason, such judgements are sometimes called introspective grammaticality judgements.
  2. The context in which the sentence was uttered.

    Criteria that do not determine grammaticality

In his study of grammaticality in the 1950s, Chomsky identified three criteria which cannot be used to determine whether a sentence is grammatical:
  1. Whether the sentence is included in a corpus,
  2. Whether the sentence is meaningful,
  3. Whether the sentence is statistically probable.
To illustrate this point, Chomsky created the nonsensical sentence in, which does not occur in any corpus, is not meaningful, and is not statistically probable. However, the form of this sentence is judged to be grammatical by many native speakers of English. Such grammaticality judgements reflect the fact that the structure of sentence obeys the rules of English grammar. This can be seen by comparing sentence with sentence. Both sentences have the same structure, and both are grammatically well-formed.
Colorless green ideas sleep furiously.
Harmless young children sleep quietly.
Sentence is grammatical yet infelicitous, because the pragmatics of the verb 'sleep' cannot be expressed as an action carried out in a furious manner. Hence, a native speaker would rate this sentence as odd, or unacceptable, because the meaning does not make sense according to the English lexicon.
Thus, for Chomsky a grammatical string is not necessarily a meaningful one. However, speakers can understand nonsensical strings by means of natural intonation. In addition, non-meaningful but grammatical sentences are often recalled more easily than ungrammatical sentences.

Grammaticality versus acceptability

When Chomsky introduced the concept of grammaticality, he also introduced the concept of acceptability. Chomsky has emphasized that "the notion of 'acceptable' is not to be confused with 'grammatical.'"
For linguists such as Hopper, who stress the role of social learning in contrast to innate knowledge of language, there has been a gradual abandonment of talk about grammaticality in favour of acceptability.
Acceptability is:
  1. A sentence that is consciously considered acceptable by both the speaker and hearer,
  2. A natural, appropriate, and meaningful sentence within a context,
  3. Related to a speaker's performance, and based on how a language would actually be used in a real situation,
  4. Speaker-oriented, depending on what speakers consider appropriate.
On the other hand, grammaticality is:
  1. A linguistic ‘string’ that follows a set of given rules,
  2. A grammatical utterance that is not necessarily meaningful,
  3. Based on a native speaker's competence or knowledge of a language,
  4. Defined by the possible outputs a particular grammar can generate.
In experiments, grammaticality and acceptability are often confused, but speakers may be asked to give their 'grammatical judgments' instead of 'acceptability judgments'. The general assumption is that a native speaker's grammar produces grammatical strings and that the speaker can also judge whether the strings are acceptable in their language.

Gradience in acceptability

The traditional categorical interpretation of grammaticality is that a sentence is either grammatical or ungrammatical. Many modern linguists, including Sprouse, support this idea.
Acceptability judgments, on the other hand, fall in a continuous spectrum. Sentences may either be clearly acceptable or clearly unacceptable, but there are also sentences that are partially acceptable. Hence, according to Sprouse, the difference between grammaticality and acceptability is that grammatical knowledge is categorical, but acceptability is a gradient scale.
Linguists may use words, numbers, or typographical symbols such as question marks or asterisks to represent the judged acceptability of a linguistic string. During a judgment task, the speaker may report the acceptability of a sentence as acceptable, marginally acceptable, unacceptable, terrible, good, etc. Degrees of acceptability can also be represented by symbols such as ?, ??, *, **, or on a scale of 0-?-*-**, with 0 being acceptable and ** being unacceptable. On a seven-point scale, speakers can rate sentences from 1 to 7.
*** The Sally hugged him the Thomas
** The Sally hugged him Thomas
* The Sally hugged Thomas
??? Which the friend Thomas has painted a picture of?
?? Which friend Thomas had painted a picture of?
? Which friend has Thomas painted the picture of?
Note that examples - are open to interpretation as judgement is based entirely on intuition, and determination of grammaticality is dependent on one's theory of what the grammar is. Therefore, different individuals may assign the same sentence different degrees of acceptability. Some linguists believe that the informal use of these symbols is problematic because the exact meaning of the symbols have never been properly defined, and their usage is riddled with inconsistencies.

Frequency affects acceptability

Acceptability is about the actual use of a speaker's language in concrete situations. Since it is speaker-oriented, it is possible to find instances of sentences that are assumed to be acceptable but ungrammatical.
Example is ungrammatical, because the preposition in is copied. The rules of English prepositions only allow sentences such as and, which show preposition pied-piping structure in, and preposition stranding structure in. Sentences and are ungrammatical but acceptable because of the frequency with which people hear the structure.
a. This world we live ...
b. This world we live in ...
c. *This world we live in ...
Although is acceptable due to a frequency affect, sentences with preposition copying are judged to be ungrammatical, as shown in.
a. This table I put the book ...
b. This table I put the book on ...
c. *This table I put the book on ...

Other factors that determine acceptability

The prevailing models on grammaticality since Chomsky postulated that the acceptability of sentences is a scale, with clearly acceptable on one side, clearly unacceptable on the other, and all manner of ranges of partial acceptability in between. To explain the scale of partial acceptability, linguists have said that phenomena other than grammatical knowledge—such as semantic plausibility, working memory limitations, etc.—account for speakers reporting acceptability on a scale. However, there are a few exceptions to this trend, including those who claim that "strength of violation" plays a role in grammaticality judgements. Examples of linguists of this persuasion include Huang's proposal that ECP violations are stronger than Subjacency violations, Chomsky's proposal that each barrier crossed leads to lower acceptability, and Optimality Theory.
Subjacency *?
Barrier *Herself likes Mary's mother
Subjacency says that you cannot relate two positions across two bounding nodes. In, we see that the movement of the wh-expression 'what' was moved past a Complementizer Phrase and a Tense Phrase to get to the specifier position of CP, thus this phrase is ungrammatical.
Within the past twenty years however, there has been a major shift in linguists' understanding of intermediate levels of acceptability. This is due to the increasing use of experimental methods to measure acceptability, making it possible to detect subtle differences along a scale of acceptability.

Norm-based evaluation

of controlled natural languages defines grammaticality as a matter of explicit consensus. On this view, to consider a string as grammatical, it should conform with a set of norms. These norms are usually based on conventional rules that form a part of a higher or literary register for a given language. For some languages, a group of experts are appointed to define and regularly update these rules.