Comma Splices And Run-Ons: Oh, How You Plague Us
The next natural lesson—if you will—in my series on grammar and punctuation is fused sentences, primarily via comma splices and run-ons. It only makes sense to move from rules on commas to comma splices, and if I am going to talk about comma splices, run-ons pair well with these. So, let’s start with explaining what a fused sentence is.
Now, for the record, some grammarians separate fused sentences as a third sentence mistake like comma splices and run-ons. However, all descriptions define a fused sentence identically to a run-on, so I generalize the two mistakes of comma splice and run-on as two types of fused sentences; that is, sentences that are combined by not punctuating correctly either through using incorrect punctuation or none at all.
Let’s now move onto understanding the comma splice.
A comma splice is a type of fused sentence where two sentences are joined by incorrect punctuation, namely the comma. Here is an example:
I went to the store, I left with more items than I planned.
In this example, two complete sentences are joined together by just a comma. The first sentence is “I went to the store.” That simple sentence has a subject (I) and verb (went). The second sentence is “I left with more items than I planned.” This, also, is a complete simple sentence with subject (I) and verb (left). Because there are two complete sentences, one cannot use a comma to connect them. There are four main options for fixing this mistake:
- use a comma and coordinating conjunction
I went to the store, but I left with more items than I planned.
- use a semicolon
I went to the store; I left with more items than I planned.
- use a semicolon and a conjunctive adverb
I went to the store; however, I left with more items than I planned.
- use a period
I went to the store. I left with more items than I planned.
In deciding how to fix a comma splice, a writer simply needs to consider which of these four options best suits the sentences, flow, and overall style of the writing. Additionally, comma splices happen with simple, compound, complex, and compound-complex sentences each. I used two simple sentences above for the sake of simplicity, but one must be sure to look out for comma splices in any type of sentence.
The comma splice is one of the mistakes I see most often in my students’ essays. Sometimes I think it is more a misuse of the comma than it is a sentence structure issue of a fused sentence; nonetheless, students regularly have comma splices. The easiest way to tell if one has a comma splice is to cover the comma up and see if what precedes the comma is a sentence and if what follows it is a sentence. If both are complete sentences, then one has a comma splice to fix in one of the four ways above.
Second to the comma splice comes the run-on, which happens when two complete sentences are joined together without any punctuation. So the example above would look like this:
I went to the store I left with more items than I planned.
See how the first part—I went to the store—basically runs into the second—I left with more items than I planned—part? There, ladies and gents, illustrates why this sentence structure issues is called a run-on. One sentence runs on to the next.
The same four revisions listed above work to fix run-ons. More often than not, though, the best method is to simply put a period in between the two sentences. Much like with the comma splice, one just has to discover where one sentence begins and ends and always have proper punctuation at the end of the sentence, which is a period more often than not.
Though these two mistakes happen often, they are also super easy to fix. The Purdue OWL provides a great, simple resource to help people with comma splices and run-ons.
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