<P> An incomplete sentence, or sentence fragment, is a set of words which 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 . A dependent clause without an independent clause is one example of an incomplete sentence . </P> <P> Some prescriptive grammars consider sentences starting with a conjunction such as but or and to be incomplete sentences, but this style prescription has "no historical or grammatical foundation". Computer grammar checkers often highlight incomplete sentences . If the context is clear from the rest of the paragraph, however, an incomplete sentence may be considered perfectly acceptable English . </P> <P> A run - on or fused sentence consists of two or more independent clauses (i.e., clauses with subject and predicate) that are joined without any appropriate punctuation . An example of such a grammatically incorrect sentence could be, "It is nearly half past five we cannot reach town before dark ." Some common remedies would be to separate the two independent clauses (between "five" and "we") with either a period (... five . We ...), a comma and conjunction (... five, and we ...), or a semicolon (... five; we ...). Joining the two independent clauses with only a comma is actually another common grammatical error, the comma splice . James Joyce's novel Ulysses employs streams of consciousness, which takes literary license by intentionally breaking this grammatical rule by use of long, punctuation - free, run - on sentences, particularly in the final chapter "Penelope". </P> <P> In general, run - on sentences occur when two or more independent clauses are joined without using a coordinating conjunction (i.e. for, and, nor, but, or, yet, so) or correct punctuation (i.e. semicolon, dash, or period), . A run - on sentence can be as short as four words, for instance: I drive she walks., or even I drive, she walks, because in this case, there are two subjects paired with two intransitive verbs . An imperative sentence like "Run walk" can be a run - on even if it only has two words . </P>

When does a sentence become a run on