Some common errors in sentence structure include comma splices, sentence fragments, run-on sentences and faulty parallelism. Writers fix these errors by expanding or dividing the sentence as necessary with appropriate elements such as punctuation and grammatical verb forms.
A comma splice occurs when a writer incorrectly uses a comma to join two or more independent clauses in a single sentence. A comma splice can usually be corrected by replacing the comma with a semicolon, separating the comma-spliced sentence into smaller sentences using appropriate punctuation, inserting a coordinating conjunction after the comma, or rearranging the sentence to use conjunctive adverbs.
A sentence fragment occurs when a writer passes off a group of words as a complete sentence. A sentence fragment can usually be fixed by expanding the fragment into a sentence using more elements or incorporating the fragment into an adjacent sentence.
A run-on sentence occurs when the writer compresses too much information into a single sentence, putting several main clauses together without proper punctuation. The solution for run-on sentences is to separate independent clauses into different sentences, join connected ideas with a semi-colon, or subordinate one of the clauses.
Faulty parallelism occurs when sentences or lists do not have parallel structure and fail to place equally important ideas within the same type of sentence pattern. This occurs most commonly when writers put gerunds and verb forms together incorrectly. To fix faulty parallelism and balance the sentence structure, the writer uses the same order and type of gerunds and verbs for all components of the list.