Glossary
comma splice
A comma splice joins two independent clauses with only a comma; a comma is not strong enough to hold two sentences together, so one of four repairs is needed.
A comma splice puts two independent clauses on either side of a comma and nothing else. The chart was missing, the nurse looked in the second drawer. Both halves could stand alone, so the comma is asked to do a period's work and cannot.
Four repairs work, and any one of them fixes the sentence. Use a period: the chart was missing. The nurse looked in the second drawer. Use a semicolon: the chart was missing; the nurse looked in the second drawer. Use a comma plus a coordinating conjunction — and, but, or, nor, for, so, yet — which is the only way a comma may join two clauses by itself. Or rewrite one clause so it is dependent: because the chart was missing, the nurse looked in the second drawer.
Its relative, the run-on, does the same thing with no punctuation at all. What separates both from a correct sentence is whether each side has its own subject and finite verb. A comma with a conjunctive adverb such as however or therefore is still a splice: those words are adverbs, not conjunctions, so they need a semicolon or a period in front of them.
Taught in
Related terms
- independent clause — An independent clause has its own subject and a finite verb and can stand alone as a sentence; a dependent clause has the same parts and still cannot.
- dependent clause — A dependent clause has a subject and a verb but opens with a word that leaves it unfinished, so it cannot stand alone as a sentence.
- antecedent — An antecedent is the noun a pronoun stands in for; if a reader cannot point back to exactly one noun, the pronoun has failed regardless of its grammar.
- sentence fragment — A sentence fragment is a group of words punctuated as a sentence that lacks a subject, a verb or a complete thought.
- run-on sentence — A run-on sentence joins two independent clauses with no punctuation at all, while a comma splice joins them with only a comma.
- semicolon — A semicolon joins two independent clauses without a conjunction, and separates list items that already contain commas.
Source: The grammar guide in this course, whose conventions follow the US Government Publishing Office's Style Manual for standard written American English, with standard grammar references for agreement, case, tense and sentence structure. The GPO manual is US federal government material, not subject to copyright in the United States. Every definition and example above was written for this course; no reference text is reproduced. (GPO Style Manual accessed 2026-10-27; definitions written 2026-10-27)