A run-on sentence
is a sentence
in which two or more independent clauses
(that is, complete sentences) are joined without appropriate punctuation or conjunction. It is generally considered to be a grammatical error, though it is occasionally used in literature and may be used as a rhetorical device. An example of a run-on is a comma splice
, in which two independent clauses are joined with a comma without an accompanying coordinating conjunction.
Some grammarians exclude comma splices from the definition of a run-on sentence
, though this does not imply that such usage is acceptable.