What is the difference between a phrase and a clause?

Phrases are groups of words that are part of a sentence but do not contain both a subject and a predicate. A clause is a group of words that contains and subject and a predicate.

A phrase is a group of words within a sentence but do not contain a subject and a predicate.

    Ex.  The old farmer came in and took off his boots.

In this sentence the phrase "the old farmer" contains the subject (farmer), and the phrase "and took off" contains the predicate (took).

A clause is a part of a sentence that contains both a subject and a predicate.

    Ex.  The bus stopped to pick me up.

In this sentence the clause "bus stopped to" contains the subject (bus) and the predicate (stopped).

A clause that cannot stand alone is dependent.

    Ex.  sauce spread on the chicken

A clause that can stand alone is an independent clause.

    Ex.  the ball bounced

With proper punctuation this clause could stand independently as would be a sentence

    Ex.  The ball bounced.

Independent clauses may be joined using coordinating conjunctions; and, or, for, nor, yet, but, so.

    Ex.  The ball bounced, and the boy ran to pick it up.

The independent clause "the ball bounced" had been joined to another independent clause "the boy ran to pick it up" by using the coordinating conjunction and.

A comma must be place before the coordinating conjunction when joining two independent clauses.

    Ex.  The dog came inside, but continued to whine.

A comma must be used to separate two or more clauses within a sentence.

    Ex.  We ate dinner, cleaned the dishes, played a game, and went to bed.

A comma must be used to separate phrases within a sentence.

    Ex.  The children had a blue truck, two red balls, and some green blocks.

If a comma is already in use in a sentence, a semicolon must be used to separate phrases within the sentence.

    Ex.  She owns a house in Atlanta, Georgia; and apartment in Houston, Texas, and a condominium in New York City, New York.

A comma must be used to before clauses that begin with who, which, that, whose or whom.

    Ex.  Rebecca, who lives on Sunnybrook Farm, is in the sixth grade.

A comma must be used before an adverb when it is used to join clauses.

    Ex.  She drove her car on the Interstate 75, where many accidents have occurred.

A comma must be used before and adverb that separates phrases.

    Ex.  He found that it was lonely at the top, as the old saying goes.

A comma must be used after an introductory clause.

    Ex.  After suffering under economy strain for many years, the United States made major policy changes.

A comma must be used after and introductory phrase.

    Ex.  After a difficult round of chemotherapy, the doctor declared his patient to be cancer free.

A comma must be used between contrasting or alternating phrases.

    Ex.  The girl used her best manners, however she was not happy.

    Ex.  A small, but well-kept house, was enough for him.

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