Sentences

In linguistics, a sentence is an expression in natural language &mdash;a grammatical and lexical unit consisting of one or more words, representing distinct and differentiated concepts, and combined to form a meaningful statement, question, request, command, etc.

As with all language expressions, sentences contain both semantic and logical elements (words, parts of speech), and also include action symbols that indicate sentence starts, stops, pauses, etc. In addition, sentences also contain properties distinct to natural language, such as characteristic intonation and timing patterns.

Sentences are generally characterized in most languages by the presence of a finite verb, e.g. "The quick brown fox jumps over the lazy dog".

Components of a sentence
A simple complete sentence consists of a subject and a predicate. The subject is typically a noun phrase, though other kinds of phrases (such as gerund phrases) work as well, and some languages allow subjects to be omitted. The predicate is a finite verb phrase: a finite verb together with zero or more objects, zero or more complements, and zero or more adverbials. See also copula for the consequences of this verb on the theory of sentence structure.

Clauses
A clause consists of a subject and a verb. There are two types of clauses: independent and subordinate (dependent). An independent clause consists of a subject verb and also demonstrates a complete thought: for example, "I am sad." A subordinate clause consists of a subject and a verb, but demonstrates an incomplete thought: for example, "Because I had to move."

By structure
One traditional scheme for classifying English sentences is by the number and types of finite clauses:


 * A simple sentence consists of a single independent clause with no dependent clauses.
 * A compound sentence consists of multiple independent clauses with no dependent clauses. These clauses are joined together using conjunctions, punctuation, or both.
 * A complex sentence consists of one or more independent clauses with at least one dependent clause.
 * A complex-compound sentence (or compound-complex sentence) consists of multiple independent clauses, at least one of which has at least one dependent clause.

By purpose
Sentences can also be classified based on their purpose:


 * A declarative sentence or declaration, the most common type, commonly makes a statement: I am going home.
 * A negative sentence or negation denies that a statement is true: I am not going home.
 * An interrogative sentence or question is commonly used to request information &mdash; When are you going to work? &mdash; but sometimes not; see rhetorical question.
 * An exclamatory sentence or exclamation is generally a more emphatic form of statement: What a wonderful day this is!
 * An imperative sentence or command tells someone to do something: Go to work at 7:30 tomorrow morning.

Major and minor sentences
A major sentence is a regular sentence; it has a subject and a predicate. For example: I have a ball. In this sentence one can change the persons: We have a ball. However, a minor sentence is an irregular type of sentence. It does not contain a finite verb. For example, "Mary!" "Yes." "Coffee." etc. Other examples of minor sentences are headings (e.g. the heading of this entry), stereotyped expressions (Hello!), emotional expressions (Wow!), proverbs, etc. This can also include sentences which do not contain verbs (e.g. The more, the merrier.) in order to intensify the meaning around the nouns (normally found in poetry and catchphrases).

Sentences that comprise a single word are called word sentences, and the words themselves sentence words.