Theoretical linguistics is that branch of linguistics that is most concerned with developing models of linguistic knowledge. Part of this endeavor involves the search for and explanation of linguistic universals, that is, properties all languages have in common. The fields that are generally considered the core of theoretical linguistics are syntax, phonology, morphology, and semantics. Phonology is often informed by phonetics, which like psycholinguistics and sociolinguistics is often not considered part of theoretical linguistics.

Phonology

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Phonology is the branch of theoretical linguistics concerned with the production and comprehension of speech sounds in language.

Morphology

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Morphology is the study of morphemes. A morpheme is held to be the smallest meaningful unit in a language. For example dog has one morpheme in it, while dogs has two, one meaning 'dog' and one meaning 'plural'. Morpheme boundaries can line up with word boundaries, especially in analytic language, where each word contains just one morpheme. In contrast, synthetic language has a high morpheme-to-word ratio, even in some cases having one word per sentence.

Syntax

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Syntax is the study of language structure and word order. It is concerned with the relationship between units at the level of morphology. Syntax seeks to delineate exactly those sentences which make up a given language, by using formal means. Syntax seeks to describe formally exactly how structural relations between elements (lexical items/words and operators) in a sentence contribute to its interpretation. Syntax uses priciples of formal logic and Set Theory to formalise and represent accurately the hierarchical relationship between elements in a sentence. Thus, in active declaritive sentences in English the subject is followed by the main verb which in turn is followed by the object (SVO). This order of elements is crucial to its correct interpretation and it is exactly this which syntacticians try to capture. They argue that there must be such a formal computational component contained within the language faculty of normal speakers of a language and seek to describe it. Abstract syntax trees are the pirmary means of describing hierarchies in sentences.

Semantics

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Semantics is the study of meaning in words and sentences.

Linguistique théorique | Językoznawstwo ogólne | Ngôn ngữ học lý thuyết