active voice

In a sentence in active voice, the subject performs the action of the verb. (See passive voice.)

I mailed a letter.


An adjective modifies a noun or pronoun.

brilliant deduction


An adverb modifies a verb, an adjective, another adverb, a phrase, or a clause.

beautifully designed, blatantly obvious, fairly easily


Agreement refers to correspondence in gender, number, case, or person between words.

They have three tickets; she has only one.


An antecedent is the word, phrase, or clause to which a pronoun refers.

a boy and his dog


An article modifies a noun, making it definite (the), or indefinite (a, an).

the first page, a poem by Keats


A clause is a group of words with a subject and a predicate.


An independent or main clause can stand alone as a sentence.

She knows.

A dependent or subordinate clause cannot stand alone as a sentence.

The woman who lives next door told me.

A restrictive or essential subordinate clause defines a noun, needs no punctuation, and usually begins with that.

Dogs that are mistreated are often nasty animals.

A nonrestrictive or dispensable subordinate clause provides nonessential information, needs punctuation, and usually begins with which.

The sun, which had been hidden for three days, burst out from behind the clouds.


A complement is a word or group of words used after a verb to complete a predicate construction.

We like to eat ice cream.


A conjunction connects words, phrases, or clauses and shows the relationship between them.


A coordinating conjunction (and, but, or) connects elements of equal importance.

almost but not quite

A correlative conjunction is a pair of coordinating conjunctions (such as both...and, either...or).

either today or tomorrow

direct object

A direct object receives the action of the verb.

The wind rattled the leaves.


A gerund is a verb form ending in –ing that acts as a noun.

She loved going to the beach.


An infinitive is a verb form used with to that acts as an adjective, adverb, or noun.

To succeed in life you must be flexible.


A modifier is a word, phrase, or clause that limits or qualifies the sense of another word or word group.

She likes homemade apple pie.



A noun names a person, place, or thing.

Plato, Rio, fire, peace


An object is a word acting like a noun that receives or is affected by the action of a verb or that follows and is governed by a preposition.

She placed the book on the table.


A participle is a verb form that acts as an adjective.


A present participle ends in –ing.

Running to the bus stop, she dropped her keys.

A past participle ends in –ed unless it is irregular.

Soothed by the soft music, she fell asleep.

passive voice

In a sentence in passive voice, the subject receives the action of the verb.

The letter was mailed by me.


A predicate expresses what is said of the subject; it includes the verb and any modifiers.

The field stretched out lazily toward the horizon.


A prefix is a word element attached to the beginning of a word that alters its meaning.



A preposition connects a noun or pronoun with another word to form a prepositional phrase that acts as an adjective or adverb.

He arrived at the meeting in a state of panic.


A pronoun substitutes for a noun.

It never occurred to me.


The subject of a sentence expresses who or what, performs the action of the verb (in the active), or receives the action of the verb (in the passive voice).

The new teacher from Iowa quickly gained his students’ respect.


A suffix is a word element added to the end of a word, forming a new word or serving as an inflectional ending.



A verb expresses the action or being of the subject.

The patient regained consciousness slowly.

Note: Entries for agreement, complement, modifier, object, prefix, and suffix come from "A Grammar Toolkit" in The American Heritage® Book of English Usage (New York: Bartleby.com, 2000

All other entries come from Bruce Ross-Larson, How to Edit Yourself (Washington, D.C.: American Writing Institute, 1999).