Ingrammar,sentence and clause structure, commonly known assentence composition, is the classification ofsentences based on the number and kind ofclauses in theirsyntactic structure. Such division is an element oftraditional grammar.
In English, sentences are composed of fiveclause patterns:[citation needed]
Sentences – which are composed of these clauses, in either "dependent" or "independent" form – also have patterns, as explained below.
Asimple sentence consists of only one clause. Acompound sentence consists of two or moreindependent clauses. Acomplex sentence has at least one independent clause plus at least onedependent clause.[1] A set of words with no independent clause may be anincomplete sentence, also called asentence fragment.
A sentence consisting of at least one dependent clause and at least two independent clauses may be called acomplex-compound sentence orcompound-complex sentence.
Sentence 1 is an example of a simple sentence. Sentence 2 is compound because "so" is considered a coordinating conjunction in English, and sentence 3 is complex. Sentence 4 is compound-complex (also known as complex-compound). Example 5 is a sentence fragment.
The simple sentence in example 1 contains one clause. Example 2 has two clauses (I don't know how to bake andI buy my bread already made), combined into a single sentence with thecoordinating conjunctionso. In example 3,I enjoyed the apple pie is an independent clause, andthat you bought for me is a dependent clause; the sentence is thus complex. In sentence 4,The dog lived in the garden andthe cat lived inside the house are both independent clauses;who was smarter is a dependent clause. Example 5 is anexclamatory sentence of an exclamative and a noun phrase but no verb. It is not a grammatically-complete clause.
A simple sentence structure contains oneindependent clause and nodependent clause.[2]
This simple sentence has one independent clause which contains onesubject,I, and oneverb,run.
This simple sentence has one independent clause which contains one subject,girl, and one predicate,ran into her bedroom. The predicate is averb phrase that consists of more than one word.
This simple sentence has one independent clause which contains one subject,dog, and one predicate,barked and howled at the cat. This predicate has two verbs, known as a compound predicate:barked andhowled. (This should not be confused with a compound sentence.)In the backyard andat the cat areprepositional phrases.
In English, acompound sentence is composed of at least two independent clauses. It does not require a dependent clause. The clauses are joined by acoordinating conjunction, a semicolon that functions as a conjunction, a colon instead of a semicolon between two sentences when the second sentence explains or illustrates the first sentence and no coordinating conjunction is being used to connect the sentences, or a conjunctive adverb preceded by a semicolon. A conjunction can be used to make a compound sentence. Conjunctions are words such asfor,and,nor,but,or,yet, andso. Examples:
The use of a comma to separate two independent clauses without the addition of an appropriate conjunction is called acomma splice and is generally considered an error (when used in English).[2] Example:
If a sentence containshomogenous members referring to another common member of the sentence, the sentence may be considered either simple[3] or compound.[4] If the homogenous members are removed, then the sentence is calledcontracted. In some languages, like Russian, a comma is not always required in a sentence with homogenous members.[5]
A complex sentence has one or more dependent clauses (also called subordinate clauses). Since a dependent clause cannot stand on its own as a sentence, complex sentences must also have at least one independent clause. In short, a sentence with one or more dependent clauses and at least one independent clause is a complex sentence. A sentence with two or more independent clauses and one or more dependent clauses is called compound-complex or complex-compound.
In addition to a subject and a verb, dependent clauses contain asubordinating conjunction or similar word. There are a large number of subordinating conjunctions in English. Some of them give the clause anadverbial function, specifying time, place, or manner. Such clauses are calledadverbial clauses.
This complex sentence contains an adverbial clause,When I stepped out into the bright sunlight from the darkness of the movie house. The adverbial clause describes when and where the action of the main clause,I had only two things on my mind, took place.
Arelative clause is a dependent clause that modifies anoun or noun phrase in the independent clause. In other words, the relative clause functions similar to anadjective.
In the first example, therestrictive relative clausewho has been deceived specifies or defines the meaning ofhim in the independent clause,Let him complain. In the second example, the non-restrictive relative clausewho have never known your family describesyou in the independent clause,You see them standing around you.
Anoun clause is a dependent clause that functions like a noun. A noun clause may function as thesubject of a clause, apredicate nominative, anobject or anappositive.
In this sentence the independent clause contains two noun clauses. The noun clauseWhat she had realized serves as the subject of the verbwas, andthat love was that moment serves ascomplement. The sentence also contains a relative clause,when your heart was about to burst.
Anincomplete sentence, orsentence fragment, is a set of words that does not form a complete sentence, either because it does not express a complete thought or because it lacks some grammatical element, such as a subject or a verb.[6][7]
An -ing fragment is a type of incomplete sentence containing a word ending in -ing that is agerund or noun, not a verb, because it lacks a helping verb. An example is, "Swimming in the ocean".[7]
Someprescriptive grammars[8] consider sentences starting with aconjunction such asbut orand to be incomplete sentences, but this style prescription has "no historical or grammatical foundation".[9] Computer grammar checkers often highlight incomplete sentences.
A run-on sentence is asentence that consists of two or moreindependent clauses (i.e. clauses that have not been made dependent through the use of a relative pronoun or a subordinating conjunction) that are joined without appropriate punctuation: the clauses "run on" into confusion. The independent clauses can be "fused", as in "It is nearly half past five we cannot reach town before dark", in which case the two independent clauses might be separated (between "five" and "we") with a period [...five. We...], a comma and conjunction (...five, and we...), or a semicolon (...five; we...). The independent clauses can be joinedinadequately with only a comma (thecomma splice).
In general, run-on sentences occur when two or more independent clauses are joined without using acoordinating conjunction (i.e.for,and,nor,but,or,yet,so) or correct punctuation (i.e. semicolon, dash, or period).[10][11][12] A run-on sentence can be as short as four words (for instance,I drive she walks, or evenI drive, she walks) because in those cases, there are twosubjects paired with twointransitive verbs. Animperative sentence like "Run walk" can be a run-on even if it has only two words.
While some sources view comma splices as a form of run-on sentences,[11] others limit the term to independent clauses that are joined without punctuation.[10][13]
According toThe American Heritage Dictionary of the English Language, the term "run-on sentence" is also used for "a very long sentence, especially one lacking order or coherence".[14]
