R.L. Trask notes that usage of the term category in linguistics "is so varied that no general definition is possible; in practice, a category is simply any class of related grammatical objects which someone wants to consider" (A Dictionary of Grammatical Terms in Linguistics, 1996)
- Derivational Morpheme and Inflectional Morpheme
- Grammatical Function
- Kinship Terms
- Part of Speech
- Phrase Structure Grammar
- Word Class
Examples and Observations:
- "The term category in some approaches [to language] refers to the classes themselves, e.g., noun, verb, subject, predicate, noun phrase, verb phrase . . .. More specifically, it refers to the defining properties of these general units: the categories of the noun, for example, include number, gender, case, and countability; of the verb, tense, aspect, voice, etc. A distinction is often made between grammatical categories, in this second sense, and grammatical functions (or functional categories), such as subject, object, complement."
(David Crystal, A Dictionary of Linguistics and Phonetics, 4th ed. Blackwell, 1997)
- Grammatical Categories and Lexical Categories
"Grammatical categories are . . . the building blocks of linguistic structure. They are sometimes called 'lexical categories' since many forms can be specified for their grammatical category in the lexicon. However, we will not use the term lexical category here because (1) the term grammatical category is more widely understood, and (2) the category of a word depends as much on how the word is used in discourse as on its conventionalized (lexical) meaning."
(Thomas E. Payne, Describing Morphosyntax: A Guide for Field Linguists. Cambridge University Press, 1997)
- The Grammatical Category of Number
"[Grammatical category is a] linguistic category which has the effect of modifying the forms of some class of words in a language. The words of everyday language are divided up into several word classes, or parts of speech, such as nouns, verbs and adjectives. It often happens that the words in a given class exhibit two or more forms used in somewhat different grammatical circumstances. In each such case, this variation in form is required by the presence in the language of one or more grammatical categories applying to that class of words.
"English nouns are affected by only one grammatical category, that of number: we have singular dog but plural dogs, and so on for most (but not all) of the nouns in the language. These forms are not interchangeable, and each must be used always and only in specified grammatical circumstances. And here is a key point: we must always use a noun in either its singular form or its plural form, even when the choice seems irrelevant; there is no possibility of avoiding the choice, and there is no third form which is not marked one way or the other. This is typically the case with grammatical categories."
(R.L. Trask, Language and Linguistics: The Key Concepts, 2nd ed., ed. by Peter Stockwell. Routledge, 2007)
- The Nature of Linguistic Categories
"It is important to keep in mind that a grammatical category is a linguistic, not a real-world, category, and that there is not always a one-to-one correspondence between the two, though they are usually closely related. For example 'tense' is a linguistic category, while 'time' is a category of the world. While past tense usually expresses past time (as in I saw a movie last night), the past-tense auxiliary in the following expresses future time: I wish you would go. And the present-tense verb of I leave tomorrow expresses future time."
(Laurel J. Brinton, The Structure of Modern English: A Linguistic Introduction. John Benjamins, 2000)
- Grammatical Categories in Traditional Grammar
"[W]ords are assigned to grammatical categories in traditional grammar on the basis of their shared semantic, morphological and syntactic properties. The kind of semantic criteria (sometimes called 'notional' criteria) used to categorise words in traditional grammar are illustrated in much-simplified form below:
- Verbs denote actions (go, destroy, buy, eat etc.)
- Nouns denote entities (car, cat, hill, John etc.)
- Adjectives denote states (ill, happy, rich etc.)
- Adverbs denote manner (badly, slowly, painfully, cynically etc.)
- Prepositions denote location (under, over, outside, in, on etc.)
(Andrew Radford, Minimalist Syntax: Exploring the Structure of English. Cambridge Univ. Press, 2004)