Run-on Sentences vs. Sentence Length


In a post about The Adverb, I mentioned our media-driven culture of quick sound bites and 140-character limitations that affect the way we communicate with words. I’ve also been hearing for years that sentence length in literature has been on a shortening trend for quite some time, even before social media was around. (Here’s just one discussion about that.)

While I, especially as a fan of pre- to mid-twentieth-century and classic literature, do enjoy my share of long sentences with a lot of great words to go with short sentences with a few great words, this post isn’t an argument about which sentence length is “better” for modern literature. What could be deemed as a better sentence length is relative, often a matter of an author’s purpose and intended audience, marketing matters, genre considerations, as well as a reader’s personal preferences and reading (skill) level.

However, I wish to point out that run-on sentences can be long or short and are determined by an improper use or lack of punctuation or conjunctions, not by sentence length.

A complete sentence, or an independent clause, includes a subject and a predicate. If a sentence has more than one independent clause without the necessary punctuation or conjunction(s) to connect them, it’s a run-on sentence.


Sentence: I read. “I” is the subject, “read” is the predicate. It’s an independent clause, a complete sentence.

Run-on Sentence: I read he reads. “I read” and “he reads” are two independent clauses. They need a conjunction and/or proper punctuation to connect them.

Run-on Sentence: I read, he reads. A comma alone is not the proper punctuation to connect two independent clauses. This grammar error is called a comma splice, which is common in run-on sentences.

Sentence: I read; he reads. These two independent clauses are connected with a semicolon. It’s a complete sentence.

Sentence: I read, and he reads. These two independent clauses are connected with a comma and a conjunction. It’s a complete sentence.

Generally, the more words that a sentence includes, the more complex it becomes, and sentence complexity is a factor that determines a work’s reading level. The longer a sentence gets, the harder it may be to understand or follow, but it does not become a run-on sentence merely because it may be “flowery” or have “too many words.” When punctuation and conjunctions are in the correct places, a sentence can go on indefinitely without being a run-on sentence.

Now, beyond works that are intended for beginning readers, I don’t think that sentences in books necessarily have to or should be mostly one length or another, or, again, that one length is inherently “better” than another. Including different sentence lengths within or among works makes for creative writing and interesting reading.

Nevertheless, as I’ve written this post chiefly to address the topic of run-on sentences, I’ll stop here. 🙂