100 Key Grammatical Terms

Brief Definitions of 100 Commonly Used Terms in English Grammar

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This collection provides a quick review of the basic terminology used in the study of traditional English grammar. For a more detailed examination of the word forms and sentence structures introduced here, click on any of the terms to visit a glossary page, where you'll find numerous examples and expanded discussions.

Abstract Noun

A noun (such as courage or freedom) that names an idea, event, quality, or concept.

Contrast with a concrete noun.

Active Voice

The verb form or voice in which the subject of the sentence performs or causes the action expressed by the verb. Contrast with passive voice.

Adjective

The part of speech (or word class) that modifies a noun or a pronoun. Adjective forms: positive, comparative, superlative. Adjective: adjectival.

Adverb

The part of speech (or word class) that is primarily used to modify a verb, adjective, or another adverb. Adverbs can also modify prepositional phrases, subordinate clauses, and complete sentences.

Affix

A prefix, suffix, or infix: a word element (or morpheme) that can be attached to a base or root to form a new word. Noun: affixation. Adjective: affixable.

Agreement

The correspondence of a verb with its subject in person and number, and of a pronoun with its antecedent in person, number, and gender.

Appositive

A noun, noun phrase, or series of nouns used to identify or rename another noun, noun phrase, or pronoun.

Article

A type of determiner that precedes a noun: a, an, or the.

Attributive

An adjective that usually comes before the noun it modifies without a linking verb. Contrast with a predicative adjective.

Auxiliary

A verb that determines the mood or tense of another verb in a verb phrase. Also known as a helping verb.

Contrast with a lexical verb.

Base

The form of a word to which prefixes and suffixes are added to create new words.

Capital Letter

The form of an alphabetical letter (such as A, B, C) used to begin a sentence or proper noun; an uppercase letter, in contrast to lower case. Verb: capitalize.

Case

A characteristic of nouns and certain pronouns that express their relationship to other words in a sentence. Pronouns have three case distinctions: subjective, possessive, and objective. In English, nouns have only one case inflection, the possessive. The case of nouns other than the possessive is sometimes called the common case.

Clause

A group of words that contains a subject and a predicate. A clause may be either a sentence (an independent clause) or a sentence-like construction within a sentence (a dependent clause).

Common Noun

A noun that can be preceded by the definite article and that represents one or all of the members of a class. As a general rule, a common noun does not begin with a capital letter unless it appears at the start of a sentence. Common nouns can be subcategorized as count nouns and mass nouns. Semantically, common nouns can be classified as abstract nouns and concrete nouns.

Contrast with a proper noun.

Comparative

The form of an adjective or adverb involving a comparison of more or less, greater or lesser.

Complement

A word or word group that completes the predicate in a sentence. The two kinds of compliments are subject complements (which follow the verb be and other linking verbs) and object complements (which follow a direct object). If it identifies the subject, the complement is a noun or pronoun; if it describes the subject, the complement is an adjective.

Complex Sentence

A sentence that contains at least one independent clause and one dependent clause.

Compound-Complex Sentence

A sentence that contains two or more independent clauses and at least one dependent clause.

Compound Sentence

A sentence that contains at least two independent clauses.

Conditional Clause

A type of adverbial clause that states a hypothesis or condition, real or imagined.

A conditional clause may be introduced by the subordinating conjunction if or another conjunction, such as unless or in the case of.

Conjunction

The part of speech (or word class) that serves to connect words, phrases, clauses, or sentences. The two main types of conjunction are coordinating conjunctions and subordinating conjunctions.

Contraction

A shortened form of a word or group of words (such as doesn't and won't), with the missing letters usually marked by an apostrophe.

Coordination

The grammatical connection of two or more ideas to give them equal emphasis and importance. Contrast with subordination.

Count Noun

A noun that refers to an object or idea that can form a plural or occur in a noun phrase with an indefinite article or with numerals. Contrast with a mass noun (or noncount noun).

Declarative Sentence

A sentence in the form of a statement (in contrast to a command, a question, or an exclamation).

Definite Article

In English, the definite article the is a determiner that refers to particular nouns. Compare to indefinite article.

Demonstrative

A determiner that points to a particular noun or to the noun it replaces. The demonstratives are this, that, these, and those. A demonstrative pronoun distinguishes its antecedent from similar things. When the word precedes a noun, it is sometimes called a demonstrative adjective.

Dependent Clause

A group of words that has both a subject and a verb but (unlike an independent clause) cannot stand alone as a sentence. Also known as a subordinate clause.

Determiner

A word or a group of words that introduces a noun. Determiners include articles, demonstratives, and possessive pronouns.

Direct Object

A noun or pronoun in a sentence that receives the action of a transitive verb. Compare to an indirect object.

Ellipsis

The omission of one or more words, which must be supplied by the listener or reader. Adjective: elliptical or elliptic. Plural, ellipses.

Exclamatory Sentence

A sentence that expresses strong feelings by making an exclamation. (Compare with sentences that make a statement, express a command, or ask a question.)

Future Tense

A verb form indicating the action that has not yet begun. The simple future is usually formed by adding the auxiliary will or shall to the base form of a verb.

Gender

A grammatical classification which in English applies primarily to the third-person singular personal pronounshe, she, him, her, his, hers.

Gerund

A verbal that ends in -ing and functions as a noun.

Grammar

The set of rules and examples dealing with the syntax and word structures of a language.

Head

The keyword that determines the nature of a phrase. For example, in a noun phrase, the head is a noun or pronoun.

Idiom

A set expression of two or more words that means something other than the literal meanings of its individual words.

Imperative Mood

The form of the verb that makes direct commands and requests.

Imperative Sentence

A sentence that gives advice or instructions or that expresses a request or command. (Compare with sentences that make a statement, ask a question, or express an exclamation.)

Indefinite Article

The determiner an or an, which marks an unspecified count noun. A is used before a word that starts with a consonant sound ("a bat," "a unicorn"). An is used before a word that starts with a vowel sound ("an uncle," "an hour").

Independent Clause

A group of words made up of a subject and a predicate. An independent clause (unlike a dependent clause) can stand alone as a sentence. Also known as the main clause.

Indicative Mood

The mood of the verb used in ordinary statements: stating a fact, expressing an opinion, asking a question.

Indirect Object

A noun or pronoun that indicates to whom or for whom the action of a verb in a sentence is performed.

Indirect Question

A sentence that reports a question and ends with a period rather than a question mark.

Infinitive

A verbal--usually preceded by the particle to--that can function as a noun, an adjective, or an adverb.

Inflection

A process of word formation in which items are added to the base form of a word to express grammatical meanings.

-ing Form

A contemporary linguistic term for the present participle and gerund: any verb form that ends in -ing.

Intensifier

A word that emphasizes another word or phrase. Intensifying adjectives modify nouns; intensifying adverbs commonly modify verbs, gradable adjectives, and other adverbs.

Interjection

The part of speech that usually expresses emotion and is capable of standing alone.

Interrogative Sentence

A sentence that asks a question. (Compare with sentences that make a statement, deliver a command, or express an exclamation.)

Interrupting Phrase

A word group (a statement, question, or exclamation) that interrupts the flow of a sentence and is usually set off by commas, dashes, or parentheses.

Intransitive Verb

A verb that does not take a direct object. Contrast with a transitive verb.

Irregular Verb

A verb that does not follow the usual rules for verb forms. Verbs in English are irregular if they do not have a conventional -ed form.

Linking Verb

A verb, such as a form of be or seem, that joins the subject of a sentence to a complement. Also known as a copula.

Mass Noun

A noun (such as advice, bread, knowledge) that names things which cannot be counted. A mass noun (also known as a non-count noun) is used only in the singular. Contrast with count noun.

Modal

A verb that combines with another verb to indicate mood or tense.

Modifier

A word, phrase, or clause that functions as an adjective or adverb to limit or qualify the meaning of another word or word group (called the head).

Mood

The quality of a verb that conveys the writer's attitude toward a subject. In English, the indicative mood is used to make factual statements or pose questions, the imperative mood to express a request or command, and the (rarely used) subjunctive mood to show a wish, doubt, or anything else contrary to fact.

Negation

A grammatical construction that contradicts (or negates) part or all of a sentence's meaning. Such constructions commonly include the negative particle not or the contracted negative n't.

Noun

The part of speech (or word class) that is used to name or identify a person, place, thing, quality, or action. Most nouns have both a singular and plural form, can be preceded by an article and/or one or more adjectives, and can serve as the head of a noun phrase.

Number

The grammatical contrast between singular and plural forms of nouns, pronouns, determiners, and verbs.

Object

A noun, pronoun, or noun phrase that receives or is affected by the action of a verb in a sentence.

Objective Case

The case or function of a pronoun when it is the direct or indirect object of a verb or verbal, the object of a preposition, the subject of an infinitive, or an appositive to an object. The objective (or accusative) forms of English pronouns are me, us, you, him, her, it, them, whom, and whomever.

Participle

A verb form that functions as an adjective. Present participles end in -ingpast participles of regular verbs end in -ed.

Particle

A word that does not change its form through inflection and does not easily fit into the established system of parts of speech.

Parts of Speech

The traditional term for the categories into which words are classified according to their functions in sentences.

Passive Voice

A verb form in which the subject receives the verb's action. Contrast with active voice.

Past Tense

A verb tense (the second principal part of a verb) indicating the action that occurred in the past and which does not extend into the present.

Perfect Aspect

A verb construction that describes events occurring in the past but linked to a later time, usually the present.

Person

The relationship between a subject and its verb, showing whether the subject is speaking about itself (first person--I or we); being spoken to (second person--you); or being spoken about (third person--he, she, it, or they).

Personal Pronoun

A pronoun that refers to a particular person, group, or thing.

Phrase

Any small group of words within a sentence or a clause.

Plural

The form of a noun that typically denotes more than one person, thing, or instance.

Possessive Case

The inflected form of nouns and pronouns usually indicating ownership, measurement, or source. Also known as genitive case.

Predicate

One of the two main parts of a sentence or clause, modifying the subject and including the verb, objects, or phrases governed by the verb.

Predicative Adjective

An adjective that usually comes after a linking verb and not before a noun. Contrast with an attributive adjective.

Prefix

A letter or group of letters attached to the beginning of a word that partly indicates its meaning.

Prepositional Phrase

A group of words made up of a preposition, its object, and any of the object's modifiers.

Present Tense

A verb tense that expresses action in the present time, indicates habitual actions or expresses general truths.

Progressive Aspect

A verb phrase made with a form of be plus -ing that indicates an action or condition continuing in the present, past, or future.

Pronoun

A word (one of the traditional parts of speech) that takes the place of a noun, noun phrase, or noun clause.

Proper Noun

A noun belonging to the class of words used as names for unique individuals, events, or places.

Quotation

The reproduction of the words of a writer or speaker. In a direct quotation, the words are reprinted exactly and placed in quotation marks. In an indirect quotation, the words are paraphrased and not put in quotation marks.

Regular Verb

A verb that forms its past tense and past participle by adding -d or -ed (or in some cases -t) to the base form. Contrast with an irregular verb.

Relative Clause

A clause introduced by a relative pronoun (​which, that, who, whom, or whose) or a relative adverb (where, when, or why).

Sentence

The largest independent unit of grammar: it begins with a capital letter and ends with a period, question mark, or exclamation point. A sentence is traditionally (and inadequately) defined as a word or group of words that expresses a complete idea and that includes a subject and a verb.

Singular

The simplest form of a noun (the form that appears in a dictionary): a category of number denoting one person, thing, or instance.

Subject

The part of a sentence or clause that indicates what it is about.

Subjective Case

The case of a pronoun when it is the subject of a clause, a subject complement, or an appositive to a subject or a subject complement. The subjective (or nominative) forms of English pronouns are I, you, he, she, it, we, they, who and whoever.

Subjunctive Mood

The mood of a verb expressing wishes, stipulating demands, or making statements contrary to fact.

Suffix

A letter or group of letters added to the end of a word or stem, serving to form a new word or functioning as an inflectional ending.

Superlative

The form of an adjective that suggests the most or the least of something.

Tense

The time of a verb's action or state of being, such as past, present, and future.

Transitive Verb

A verb that takes a direct object. Contrast with an intransitive verb.

Verb

The part of speech (or word class) that describes an action or occurrence or indicates a state of being.

Verbal

A verb form that functions in a sentence as a noun or a modifier rather than as a verb.

Word

A sound or a combination of sounds, or its representation in writing, that symbolizes and communicates a meaning and may consist of a single morpheme or a combination of morphemes.

Word Class

A set of words that display the same formal properties, especially their inflections and distribution. Similar to (but not synonymous with) the more traditional term part of speech.