Classification of sentence

Parts of Speech

One way to begin studying basic sentence structures is to consider the traditional parts of speech (also called word classes): nouns, pronouns, verbs, adjectives, adverbs, prepositions, conjunctions, and interjections. Except for interjections ("ouch!"), which have a habit of standing by themselves, the parts of speech come in many varieties and may show up just about anywhere in a sentence. To know for sure what part of speech a word is, we have to look not only at the word itself but also at its meaning, position, and use in a sentence.

Subjects, Verbs, and Objects

The basic parts of a sentence are the subject, the verb, and (often, but not always) the object. The subject is usually a noun—a word that names a person, place, or thing. The verb (or predicate) usually follows the subject and identifies an action or a state of being. An object receives the action and usually follows the verb.

Adjectives and Adverbs

A common way of expanding the basic sentence is with modifiers—words that add to the meanings of other words. The simplest modifiers are adjectives and adverbs. Adjectives modify nouns, while adverbs modify verbs, adjectives, and other adverbs.

Prepositional Phrases

Like adjectives and adverbs, prepositional phrases add meaning to the nouns and verbs in sentences. A prepositional phrase has two basic parts: a preposition plus a noun or a pronoun that serves as the object of the preposition.

Four Basic Sentence Structures

There are four basic sentence structures in English:

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  A simple sentence is a sentence with just one independent clause (also called a main clause): Judy laughed.
  
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  A compound sentence contains at least two independent clauses: Judy laughed and Jimmy cried.
  
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  A complex sentence contains an independent clause and at least one dependent clause: Jimmy cried when Judy laughed.
  
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  A compound-complex sentence contains two or more independent clauses and at least one dependent clause: Judy laughed and Jimmy cried when the clowns ran past their seats.