Writing Mini-Lessons: How to Correct Comma Splices

Definition: A comma splice is an error that occurs when a writer attempts to hook two sentences together with a comma.

The comma splice is one of the most common errors sixth grade students make in their writing. As a punctuation mark, the comma is not strong enough to connect to sentences. A comma signals a brief break or pause, but not a complete stop. Remember, the word comma comes from the Greek word meaning “little knife.” It’s not a big knife. A comma is strong enough to connect groups of words, like phrases and clauses, to sentences, but it’s not strong enough to connect two sentences. When a writer attempts to jam two sentences together by inserting a comma between them, the error is called a comma splice, and results in a run-on sentence.

Here are some examples of comma splices:

There is a test to determine whether a construction is a comma splice or if it is a legal sentence with a comma in it: can the group of words on either side of the comma stand alone as complete sensible sentences? If they cannot, then the sentence is not a comma splice. However, if they can, then a comma splice exists. Below are a few options for correcting comma splices:

Scour your writing for comma splices, and then experiment with the different ways to fix those splices.

When you write, remember to include commas where they are needed and to omit commas where they are not needed. Here are some rules to remember when you copyedit:

Some Comma Rules to Remember

  1. Use a comma to separate the elements in a series (three or more things): The family needs clothing, food, and shelter. In fiction, you use a comma before the and. In journalism, you do not.
  2. Use a comma + a coordinating conjunction (and, but, for, nor, yet, or, so) to connect two independent clauses or two complete sentences: The owl is a nocturnal animal, and it sleeps during the day. I thought I could stay awake till midnight, but I fell asleep much earlier. The comma should not follow the and or but (e.g., The owl is a nocturnal animal and, it sleeps during the day.)
  3. Use a comma to set off most introductory phrases.  Here is a simple definition of a phrase: a  word  group that lacks either a subject or a predicate or both: Fearing an accident, she drove carefully during the stormy weather, or In a panic, he rummaged through his pockets in search of his wallet.
  4. Use  a comma when a subordinate clause is as an introductory element of a sentence and modifies a word or words in the main clause: Although Susan had woken up earlier than usual, she was still late for school.
  5. Use a comma to set off parenthetical elements: The Paradise Bridge, which spans the Petaluma River, is falling down.  A parenthetical element is a nonrestrictive element: a part of a sentence that can be removed without changing the essential meaning of that sentence. The parenthetical element is sometimes called “added information.” You can decide whether to use commas in such cases by removing the phrase. If the sentence still makes sense and is complete, you separate the phrase with commas. An appositive, a re-naming or amplification of a word that immediately precedes it, is almost always treated as a parenthetical elements. An absolute phrase is always treated as a parenthetical element, as is an interjection. An addressed person’s name, or vocative, is also always parenthetical. When both a city’s name and that city’s state or country’s name are mentioned together, the state or country’s name is treated as a parenthetical element: Paris, France, is often called “The City of Lights.”
  6. Use a comma with a prepositional phrase that starts with prepositions that take objects: about, above, at, before, below, or as we used to say, to remember: over, under, around and through: Before learning to walk, most children first learn to crawl.
  7. Use a comma before which but not before that: I studied at the university, which was in town, or I studied at the university that was in town.
  8. Use a comma to separate coordinate adjectives. You could think of this as “That tall, distinguished, good-looking fellow” rule (as opposed to “the little old lady”). If you can put an and or a but between the adjectives, a comma will probably belong there. For instance, you could say, I live in an ancient and run-down house. So you would write, I live in an ancient, run-down house.
  9. Use a comma to set off quoted elements: Summing up this her opinion of commas, Gertrude Stein wrote, “well at the most a comma is a poor period that lets you stop and take a breath...” If an attribution of a quoted element comes in the middle of the quotation, two commas will be required. Be careful not to use commas to set off quoted elements introduced by the word that or quoted elements that are embedded in a larger structure. Furthermore, instead of a comma, use a colon to set off explanatory or introductory language from a quoted element that is either very formal or long.
  10. Use commas to set off phrases that express contrast: Some say the world will end in ice, not fire, or It was her money, not her charm or personality, that first attracted him.
  11. Use a comma to avoid confusion. This is often a matter of consistently applying rule #3: Outside,the lawn was cluttered with hundreds of broken branches instead of this: Outside the lawn was cluttered with hundreds of broken branches.
  12. Use a comma for typographical reasons: Between a city and a state (Petaluma, California), a date and the year (June 8, 2000), a name and a title when the title comes after the name (Mr. Eric Pratt, Professor of Marketing), and in long numbers (92,545). Although you will often see a comma between a name and suffix — Eric Pratt, Jr.; Richard Harrison, III — this comma is no longer regarded as necessary by most copy editors, and some individuals — such as Martin Luther King Jr. — never used a comma there at all.