Comma Splice
A comma splice is a sentence-boundary error in which a comma alone joins independent clauses. The repair depends on the relationship between the clauses: use a period, a semicolon, or a comma plus an appropriate coordinating conjunction.
A comma splice occurs when two independent clauses are joined with only a comma. Standard repairs include separating the clauses, using a semicolon, or adding an appropriate coordinating conjunction after the comma.
Key details
Important caveats
Scope Boundary
Not every comma between clauses is a splice: a comma can be correct when a coordinating conjunction links the independent clauses or when the clause structure is different.
Further guidance
Application
Repair a comma splice with a period, a semicolon, or a comma plus a coordinating conjunction such as “and,” “but,” or “so,” as the meaning requires.
Core Rule
Do not use a comma by itself to join two independent clauses in standard edited prose.
Practical Application
When two independent clauses are joined by only a comma, repair the comma splice according to the intended relationship: use a period for separation, a semicolon for close coordination, or a comma plus an appropriate coordinating conjunction.
Reader Check
Can each side of the comma stand alone as a complete sentence, and is there no coordinating conjunction joining them?
Worked Example
Change “The server restarted, the site recovered” to “The server restarted, and the site recovered,” “The server restarted; the site recovered,” or two separate sentences, depending on emphasis.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Run-ons, Comma Splices, and Fused Sentences — Purdue OWL (opens in a new tab)Purdue Online Writing Lab · University writing-center guidance defining comma splices and showing standard repairs for independent clauses.