Sentences are composed of clauses and phrases, which are assortments of words forming conceptual units. Clauses contain both a subject and a verb, while phrases do not.
A clause is a part of a sentence that contains both a subject and a verb. The four main types of clauses are independent clauses, dependent clauses, relative clauses, and noun clauses.
An independent clause (also known as a main clause) is a clause that can stand on its own as a complete sentence.
A dependent clause (also known as a subordinate clause) is a clause that cannot stand on its own as a complete sentence. Since it is a clause, though, it will still contain a subject and a verb. It must be attached to an independent clause in order to create a complete sentence.
A relative clause (also known as an adjective clause) provides information about the noun or phrase that precedes it. Relative clauses begin with relative pronouns: who, whom, whose, which, what, that. Relative clauses are a type of dependent clause, since they cannot stand alone as a sentence.
There are two types of relative clauses: restrictive and nonrestrictive clauses.
A restrictive clause identifies the word or phrase it modifies. It is essential to the meaning of the sentence and does not use commas.
The relative pronouns who or that are used to introduce a restrictive clause.
Nonrestrictive clauses are clauses that can be removed without altering the meaning of the sentence. They provide additional information, rather than directly modifying a word, and are set off by commas. Unlike a restrictive clause, a nonrestrictive clause is not essential to the meaning of the sentence.
Do not use the relative pronoun that for a nonrestrictive clause.
A noun clause is a clause that acts like a noun. It is a type of dependent clause, since it cannot stand alone as a sentence. If you substituted in a single noun for the noun clause, the sentence would still make sense. Remember, a noun clause must contain a subject and a verb.
An adverbial clause is a clause that acts as an adverb. It is a type of dependent clause. Adverbial clauses contain both a subject and a verb.
Phrases are groups of words that act as a unit in a sentence. They do not contain both a subject and a verb. There are many types of phrases, including noun, adjective, adverb, prepositional, infinitive, participle, gerund, and absolute phrases. The name of the type of phrase usually refers to either the phrase’s function or the part of speech that starts the phrase.
Phrases do not contain both a subject and a verb.
A noun phrase functions as a noun, and contains a noun as well as its modifiers.
An adjective phrase is a group of words modifying a noun or a pronoun.
Adverbial phrases modify verbs and tell us where, when, why, and how. They may not contain an adverb, but instead act the same way an adverb does.
Prepositional phrases begin with a preposition – a word that shows the relationship between a noun and another word. Some prepositions include above, about, behind, in, on, to.
A prepositional phrase contains a preposition and its object. Prepositional phrases can act as either adjectives or adverbs. Some prepositional phrases are adjective phrases or adverb phrases, but not all adjective or adverb phrases are prepositional phrases.
An infinitive phrase is a phrase that starts with the infinitive form of a verb. The infinitive form is the basic form of the verb which is preceded by the word to, such as “to run.” Infinitive phrases can also act as nouns, adjectives, and adverbs.
Infinitives that are preceded by words such as can, could, may, might, must, shall, should, will, or would do not include to.
An appositive phrase identifies or describes the noun next to it by expanding upon it. This is different than an adjective phrase, which simply describes a noun. An appositive may be a type of noun phrase.
A participle phrase is a phrase that starts with a participle and is used to describe a noun. A participle is a verb that is used as an adjective, usually ending in “-ing” (present) or “-ed” (past).
A gerund phrase is a phrase that starts with a gerund. A gerund is a noun derived from a verb ending in “-ing.” Note that this looks very similar to prepositional phrases, but in this case, the "-ing" verb is acting as a noun.
An absolute phrase is a phrase that describes or modifies an entire independent clause. It is comprised of a noun, a participle, and any modifiers.