A sentence is a group of words that expresses a complete thought about something or someone. Every sentence must contain two basic parts: a subject and a predicate.

The subject of a sentence names a person, place, or thing and tells whom or what the sentence is about. It identifies the performer or receiver of the action expressed in the predicate.

The noun or pronoun that names what the sentence is about is called the simple subject.

The simple subject of an imperative sentence is understood as you, but you is not stated directly.

The complete subject is the simple subject plus its modifiers—words that describe, identify, qualify, or limit the meaning of a noun or pronoun.

A sentence with a compound subject contains two or more simple subjects joined by a coordinating conjunction (and, but, for, nor, or, so, or yet).

The predicate of a sentence indicates what the subject does, what happens to the subject, or what is said about the subject. The predicate, then, can indicate an action or a state of being.

The simple predicate is the main verb along with its helping verbs.

The complete predicate consists of the simple predicate plus its modifiers and any objects or complements. (See below for more about complements.)

A compound predicate contains two or more predicates that have the same subject and that are joined by and, but, or, nor, or another conjunction (see 1f).

A direct object is a noun or pronoun that receives the action of a verb. A direct object answers the question, What? or Whom?

The noun reel answers the question, What did he play?

The noun quarterback answers the question, Whom did they jeer?

An indirect object is a noun or pronoun that names the person or thing to whom or for whom something is done.

A complement is a word or group of words that describes a subject or object and completes the meaning of the sentence. There are two kinds of complements: subject complements and object complements.

A linking verb (such as be, become, feel, seem, or taste) connects the subject of a sentence to a subject complement, a noun, a noun phrase, or an adjective that renames or describes the subject.

An object complement is a noun, a noun phrase, or an adjective that modifies or renames the direct object. Object complements appear with transitive verbs (such as name, find, make, think, elect, appoint, choose, and consider), which express action directed toward something or someone.

A phrase is a group of related words that lacks a subject, a predicate, or both. A phrase cannot stand alone as a sentence. Phrases can appear at the beginning, middle, or end of a sentence and can help make your writing more detailed and interesting.

There are four common types of phrases: prepositional phrases, verbal phrases, appositive phrases, and absolute phrases.

A prepositional phrase consists of a preposition (in, above, with, at, behind ), the object of the preposition (a noun or pronoun), and any modifiers of the object. Prepositional phrases usually function as adjectives or adverbs to tell more about people, places, objects, or actions. They can also function as nouns. A prepositional phrase generally adds information about time, place, direction, or manner.

Each of the following sentences has been edited to include a prepositional phrase or phrases that expand the meaning of the sentence by adding detail.

A verbal is a verb form used as a noun (the barking of the dog), an adjective (a barking dog), or an adverb (continued to bark). It cannot be used alone as the verb of a sentence, however. The three kinds of verbals are participles, gerunds, and infinitives. A verbal phrase consists of a verbal and its modifiers.

Participles and participial phrases. All verbs have two participles: present and past. The present participle is the -ing form of a verb (being, hoping, studying). The past participle of most verbs ends in -d or -ed (hoped, consisted ). The past participle of irregular verbs has no set pattern (been, ridden). Both the present participle and the past participle can function as adjectives modifying nouns and pronouns.

A participial phrase, which consists of a participle and its modifiers, can also function as an adjective in a sentence.

Gerunds and gerund phrases. A gerund is the present participle, or -ing form, of a verb that functions as a noun in a sentence.

A gerund phrase consists of a gerund and its modifiers. Like a gerund, a gerund phrase is used as a noun and can therefore function in a sentence as a subject, a direct object, an indirect object, an object of a preposition, or a subject complement.

Infinitives and infinitive phrases. An infinitive is the base form of a verb preceded by to: to study, to sleep. An infinitive phrase consists of the infinitive plus any modifiers or objects. An infinitive phrase can function as a noun, an adjective, or an adverb.

Sometimes the to in an infinitive phrase is understood but not written.

Note: Be sure to distinguish between infinitive phrases and prepositional phrases beginning with the preposition to. In an infinitive phrase, to is followed by a verb (to paint); in a prepositional phrase, to is followed by a noun or pronoun (to a movie).

An appositive is a word that explains, restates, or adds new information about a noun. An appositive phrase consists of an appositive and its modifiers.

The appositive phrase adds information about the noun Ben Affleck.

An absolute phrase consists of a noun or pronoun and any modifiers, usually followed by a participle. An absolute phrase modifies an entire sentence, not any particular word or words within the sentence. It can appear anywhere in a sentence and is set off from the rest of the sentence with commas.

A clause is a group of words that contains a subject and a predicate. A clause is either independent (also called main) or dependent (also called subordinate). An independent clause can stand alone as a grammatically complete sentence.

A dependent clause has a subject and a predicate, but it cannot stand alone as a grammatically complete sentence because it does not express a complete thought. A dependent clause usually begins with either a subordinating conjunction or a relative pronoun that connects it to an independent clause.

Common Subordinating Conjunctions

Relative Pronouns

When joined to independent clauses, dependent clauses can function as adjectives, adverbs, or nouns and are known as adjective clauses (also called relative clauses), adverb clauses, or noun clauses. A noun clause can function as a subject, an object, or a complement.

Relative pronouns are generally the subject or object in their clauses. Who and whoever change to whom and whomever when they function as objects. Sometimes the relative pronoun or subordinating conjunction is implied or understood rather than stated.

That is the understood relative pronoun in the subordinate clause.

A dependent clause may contain an implied predicate. When a dependent clause is missing an element that can be inferred from the context of the sentence, it is called an elliptical clause.

The predicate disturbed them is implied.

A sentence can be classified as one of four basic types: simple, compound, complex, or compound-complex.

A simple sentence has one main or independent clause and no subordinate or dependent clauses. A simple sentence contains at least one subject and one predicate. It may have a compound subject, a compound predicate, and various phrases, but it has only one clause.

A compound sentence consists of two or more independent clauses and no dependent clauses. The two independent clauses are usually joined with a comma and a coordinating conjunction (and, but, for, nor, or, so, or yet).

Sometimes two clauses are joined with a semicolon and no coordinating conjunction.

Or they may be joined with a semicolon and a conjunctive adverb (such as nonetheless or still ), followed by a comma.

A complex sentence has one independent clause and one or more dependent clauses. The dependent clauses usually begin with a subordinating conjunction or a relative pronoun (see 2c for a list).

A compound-complex sentence contains two or more independent clauses and one or more dependent clauses.