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In formal, academic contexts, writing complete sentences (also called independent clauses or sentences) is important to ensure your reader understands your writing. A complete sentence must at least contain a subject, a verb, and a complete idea. Four types of sentence structures are illustrated in the table below. In each of the following examples, the independent clause is bolded, and the dependent clause or phrase is italicized. Keep in mind that dependent clauses/phrases can often go before or after the independent clause as long as your wording is logical.
|Simple||1 independent clause||They didn't provide a lot of background information.|
1 independent clause + 1 dependent clause/phrase (option 1)
1 dependent clause/phrase + 1 independent clause (option 2)
They dove right into the methods even though they didn't provide a lot of background information. (option 1)
Even though they didn't provide a lot of background information, they dove right into the methods. (option 2)
|Compound||1 independent clause + 1 independent clause||They didn't provide a lot of background information, but they dove right into the methods.|
|Complex-Compound||2 or more independent clauses + 1 or more dependent clauses/phrases||They didn't provide a lot of background information, but they dove right into the methods, providing some more information about the research.|
To see rules regarding comma and semicolon usage for each type of structure, please see our Commas and Semicolons chapter.
Problems arise when writers do not include all the required elements to make a complete sentence. Three common problems include comma splices, run-on sentences, and sentence fragments. You have many options to choose from when correcting these mistakes, but which option you choose can change the tone and interpretation of your writing, so make your choice carefully. Regardless of how you revise, make sure the sentence is still grammatical afterward.