The term "grammatical category" refers to specific properties of a word that can cause that word and/or a related word to change in form for grammatical reasons (ensuring agreement between words).
For example, the word "boy" is a noun. Nouns have a grammatical category called "number". The values of number are singular (one) and plural (two or more).
- The boy is playing.
- The boys are playing.
In sentence 1, "boy" is in its basic form, giving its "number" the value of singular. There is one boy and the related auxiliary verb "to be" is in the singular form (is).
In sentence 2, the form of "boy" has changed to "boys", giving its "number" the value of plural. There is more than one boy and the related "to be" is in the plural form (are).
In the above example, the "number" of "boy" influences the form of boy, and also influences the form of a related word (be). "Number" is a "grammatical category".
English has over twenty grammatical categories. Below we list the most common ones for English learners and summarise their main features.
Number is a property of nouns and pronouns, and indicates quantity. Number has two values:
- singular: indicates one only
- plural: indicates two or more
Case is a property of pronouns and nouns, and expresses their relationship to the rest of the sentence. Case has three values (two of which do not apply to nouns):
- subjective (pronouns only): when the word is the subject
- objective (pronouns only): when the word is the object
- possessive (pronouns and nouns): when the word indicates possession (ownership)
Natural gender is a property of pronouns, and differentiates the sexes. Natural gender has three values:
- masculine: indicates male
- feminine: indicates female
- neuter: indicates everything else
Note that Old English had "grammatical gender" where words themselves had gender. Remnants of this are found in "natural gender", which is based on the sex of people rather than the gender of words.
Person is a property of pronouns, and differentiates participants in a conversation. Person has three values:
- first person: refers to the speaker
- second person: refers to the hearer
- third person: refers to all other people or things
Tense is a property of verbs, and most closely corresponds with location in time. Tense has two values:
- past: indicates before now
- present: indicates now (and sometimes before and after now)
Note that "future tense" is not shown here because strictly-speaking it is not a tense but a structure to talk about the future (after now).
Aspect is a property of verbs, and expresses our view of the time structure of an activity or state. Aspect has three values:
- simple: the time has no structure
- continuous: expresses ongoing action
- perfect: expresses completed action
|verb||they work||they are working||they have worked|
Mood is a property of verbs, and relates to the speaker's feelings about the reality of what he is saying. Mood has three values:
- indicative: expresses simple statement of fact
- imperative: expresses command
- subjunctive: expresses something desired or imagined
|verb||James stood up.||Stand up!||We insist that he stand.|
|Is it quiet enough?||Be quiet!||It is essential that you be quiet.|
Voice is a property of transitive verbs*, and expresses the relationship of the subject to the action. Voice has two values:
- active: the subject does the action
- passive: the subject receives the action
|transitive verb||The cat ate the mouse.||The mouse was eaten by the cat.|
*A transitive verb can take a direct object. (An intransitive verb does not take a direct object.)
Degree is a property of gradable adjectives and adverbs, and indicates amount. Degree has three values:
- positive: indicates a basic quality
- comparative: indicates a greater quality
- superlative: indicates the maximum quality
|gradable adjective||happy||happier||the happiest|
|gradable adverb||carefully||more carefully||the most carefully|