Run-on Sentences and Sentence Fragments

Run-on sentences and sentence fragments are grammatical errors in writing, but they make a lot of sense because we often speak using both of them fluently without any lack of understanding. The problem is that in speech, it’s easier to “read” these sentence types. We can use body language, intonation, facial expression, and speaking rhythm to follow the speaker’s train of thought. Punctuation is designed to do the same thing in writing, but it is just not as effective. Therefore, when we have run-ons and fragments in our essays, they are difficult to follow or understand.

In a run-on sentence, you have more than one subject (main noun) + predicate (main verb) pair that are not connected with a conjunction (and/or/for/nor/but/so/yet) or a semicolon.

In a sentence fragment, the subject (main noun) or predicate (main verb) are missing.

Most people think fragments are short and run-ons are long, but that’s often not the case. The issue is their structure, not their length. Here are some examples of this common writing weakness:

My mother always had reading books and writing material in reach even my coloring books had some kind of reading in them. This is a run-on. We have two subject/predicate pairs (mother had; books had) with no conjunction or semicolon between them. The reason you want to avoid sentences like this is that they make it difficult for your reader to follow. The change in subject, from her mother to the books, is awkward.

It would show them that not only were there Republicans that were against this law but also Democrats. Since there is an argument about how the Republicans were the only ones fighting against this law. The second sentence is a fragment. While it does contain a subject/predicate pair (there is), it’s prefaced with “since,” which signals to our reader that this is just one clause in a sentence. If I said, “Ever since I was a little girl,” you’d expect something after it, even though I do technically have both a subject (I) and a predicate (was).

I’ve always been a shy person even with my own family. Always being that one person that would rather stay quiet and pay attention, than being that one person to stand out from the rest. The rather long second sentence is a sentence fragment. It doesn’t have a subject or even a clear predicate. It should say something like “I would rather stay quiet and pay attention, rather than stand out,” but instead it starts with a gerund (-ing) verb. Gerunds cannot be the predicate of a sentence without a helping verb. So, Needing this done today is not a complete sentence but I am needing this done today is, because of the helping verb “am.”

This improper use of a gerund is a common issue with sentence fragments, which we see again in this example:

Andrew Rosenthal, firing off reasons for being upset, along with descriptors that invoke imagery of this being a long time in the making. The subject of this sentence is Andrew Rosenthal, but there’s no predicate, making this a sentence fragment. We have a gerund, “firing,” but no helping verb, so this structure makes the reader expect something after the sentence ends. If I say Courtney, feeling hurt about the email, you generally expect a verb after that clause. Say, Courtney, feeling hurt about the email, went to calm down in the library. The problem with this sentence, then, is not that it’s incorrect grammar. It’s that the error actually makes this sentence confusing. The reader reaches the end of it and is expecting more than there is.

The fastest way to catch run-ons and fragments is to read your essay aloud and be watching out for them. Make sure each sentence has a subject and predicate, and if there’s more than one pair, that they are separated by either a conjunction (and, or, for, nor, but, so, yet) or a semicolon (never both). For example, these two sentences have two subject + predicate pairs and are grammatically sound:

Every Christmas I would get 10-15 books, and then I promptly frustrated my mother by reading them all in two weeks. First subject and predicate are “I would get” and the second is “I frustrated.” They are linked by a comma and a conjunction (and).

The professionalization of science correlates with the rise of “scientific romances” or science fiction; this is no coincidence. The first subject and predicate are “professionalization correlates” and the second are “this is.” They are linked by a semicolon with no conjunction.

Review the rules for semicolon use, since it is a commonly misused punctuation mark.

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Written by Courtney Stoker