What is a sentence?

A sentence is the basic unit of writing and expression. It contains at least a subject and a predicate and is grammatically complete and independent.

The Rules

To make a sentence:

There must be a subject.
- The exception to this rule is a class of sentences called imperatives, in which the subject is usually implied (Faigley 369).
- English is unlike several other languages in requiring a subject for sentences. In Spanish, Chinese, and Japanese, for example, speakers can say the equivalent of is raining without inserting a subject. But speakers of English must insert a dummy subject in such cases (it is raining) even though it refers to nothing (Faigley 370).
The subject is a person, place, or thing “that either performs an action or is described” (Glenn 292).
There must be a predicate.
The predicate expresses the action initiated by the subject or makes a comment about the subject (Glenn 292).
Always start with a capital letter and end with one of these punctuations: period, exclamation point, or question mark.

Usage

The four functions of sentences are demonstrated by the following:

An imperative sentence gives instructions.

Go make me a bowl of cereal.

A declarative sentence reports information or states facts.

We are out of cereal.

An interrogative sentence is a question and it elicits information or introduces topics.

Would you go to the store and get some cereal?

An exclamatory sentence portrays emotions.

The car is on fire!

The four types of sentences are determined by the nature and number of clauses they contain.

A simple sentence is one independent clause with no subordinate clauses (Hacker 464).

The hamster rolls around in its toy ball.

A compound sentence consists of two or more main clauses and no subordinate clause (Aaron 167). The independent clauses are usually joined with a comma and a coordinating conjunction (and, but, or, nor, for, so, yet) or with a semicolon (Hacker 464).

Yuki is a white dog, but Dixie is a black dog.

A complex sentence is composed of one independent clause and one or more subordinate clauses (Hacker 464).

When you stay up late, it is hard to stay awake all day.

A compound-complex sentence has the characteristics of both the compound sentence (two or more main clauses) and the complex sentence (at least one subordinate clause) (Aaron 168).

While the crickets chirped, one owl sat on a branch, and the other owl hunted.

Links

Works Cited

Glenn, Cheryl et al. The Writer’s Harbrace Handbook. 2nd ed. Boston: Thomson Wadsworth, 2005.
Faigsley, Lester. The Brief Penguin Handbook. Pearson Education, Inc., 2003.
Aaron, Jane E. The Little Brown Compact Handbook. 5th ed. Pearson Education, Inc., 2004.
Hacker, Diana. A Writer’s Reference. 5th ed. Boston: Bedford/St. Martin’s, 2003.