A grammatical category is a class of units (such as noun and verb) or features (such as number and case) that share a common set of characteristics. They are the building blocks of language, allowing us to communicate with one another. There are no hard and fast rules for what defines these shared traits, however, making it difficult for linguists to agree on precisely what is and is not a grammatical category.
As the linguist and author R.L. Trask put it, 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."
That said, there are some strategies you can use to group words into categories based on how they function in the English language (think of parts of speech).
Identifying Grammar Groups
One of the simplest ways to create grammatical categories is by grouping words together based on their class. Classes are word sets that display the same formal properties, such as inflection or verb tense. Put another way, grammatical categories can be defined as sets of words with similar meanings (called semantics).
There are two families of classes, lexical and functional. Nouns, verbs, adjectives, adverbs, and adjectives fall into this class. Determiners, particles, prepositions, and other words denoting position or spatial relationships are part of the functional class. Using this definition, you can create grammatical categories like this:
- 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.)
Grammar groups can be further divided, depending on a word's defining properties. Nouns, for instance, can be further subdivided into number, gender, case, and countability. Verbs can be subdivided by tense, aspect, or voice.
Unless you're a linguist, you probably won't spend much time thinking about how words can be classified based on how they function in the English language. But just about anyone can identify basic parts of speech. Be careful, though. Some words have multiple functions, such "watch," which can function as both a verb ("Watch out over there!") and a noun ("My watch is broken."). Other words, such as gerunds, may appear to be one part of speech (a verb) and yet function differently (as a noun). In these cases, you'll need to pay close attention to the context in which such words are used in writing or speech.
- David Crystal, A Dictionary of Linguistics and Phonetics, 4th ed. Blackwell, 1997
- Thomas E. Payne, Describing Morphosyntax: A Guide for Field Linguists. Cambridge University Press, 1997
- R.L. Trask, Language and Linguistics: The Key Concepts, 2nd ed., ed. by Peter Stockwell. Routledge, 2007
- Laurel J. Brinton, The Structure of Modern English: A Linguistic Introduction. John Benjamins, 2000
- Andrew Radford, Minimalist Syntax: Exploring the Structure of English. Cambridge University Press, 2004