The English grammar rules of run-on sentences are a mystery to many would be writers.

Ask your average writer to define “run-on sentence” and he will probably tell you that it’s a sentence that’s too long, that keeps going, that runs on and on. Sure, that’s part of the problem. But even our canonized writers of American Literature have examples of very lengthy sentences; Faulkner has whole paragraphs comprised of just one sentence, and Walt Whitman has several sentences in “Song of Myself” that last a few pages each!

Are these run-on sentences? No, the trick is in the punctuation. So, here’s a bit of advice on the English grammar rules of run-on sentences.

A run-on sentence, or a fused sentence, is merely two sentences joined together incorrectly. When two independent clauses are joined, they should have either some kind of punctuation and/or a coordinating conjunction.

Let’s look at some examples.

Here are two independent clauses: 1) My mother loves to cook. 2) My father enjoys her meals. Two independent clauses because we have two full thoughts – two subject and verb combinations. Now, we can make these one sentence a couple of ways. We can connect them with one of the FANBOYS (for, and, nor, but, or, yet, so) and a comma, like this:

My mother loves to cook, and my father enjoys her meals.

Or, we can use a semi-colon, like this:

My mother loves to cook; my father enjoys her meals.

Or we can leave them like they are and call it correct. But what we cannot do is simply tag the second onto the first, like this:

Bad Example: My mother loves to cook my father enjoys her meals.

(This sounds like my mother loves to cook my father!) It breaks the rules of English grammar, becomes a run-on sentence, and is a leading cause of baldness among English teachers.

Neither can we use a simple comma to join them; that creates a comma splice.

Bad Example: My mother loves to cook, my father enjoys her meals.

If you want to drive a composition teacher crazy, use commas splices in your writing. Even at the college level, a comma splice can put your paper into the automatic fail pile.

Simple enough, right? So let’s take the following sentence and determine if it’s a run-on sentence or not.

Many times in my life, I have heard that writing is very easy, so I try my hand at writing, yet I seem to have problems remembering the rules of English as I go; I often find myself wishing I were a walking encyclopedia of grammar rules.

Run-on sentence? Not at all. Lengthy, sure, but grammatically, it’s fine!

Now look at this one:

I like to write so I write everyday and I use the computer because I can’t write well by hand and the words come at me so fast I can’t get them all down before I forget what I wanted to say so I type really fast and I need to practice my typing because I’m not very good at it.

Run-on sentence? You bet! It has too many conjunctions with absolutely no punctuation, and it changes thoughts throughout. Let’s try to fix it.

I like to write, so I write everyday. I use the computer because I can’t write well by hand, and the words come at me so fast, I can’t get them all down before I forget what I wanted to say. So I type really fast, but I need to practice my typing because I’m not very good at it.

Although it’s better grammatically, it still changes ideas too quickly. Let’s try rewording it, too.

I like to write, so I write everyday. I use the computer because I can’t write well by hand. The words come at me so fast that I can’t get them all down before I forget what I wanted to say. I type really fast, but I should practice my typing because I’m not very good at it.

It still says the same thing, but it’s a bit easier to read now, don’t you think? That’s what the rules of grammar are for – making things easier to understand.

So before you publish anything, even a blog, read through it carefully. If the ideas need to be in two different sentences, do so. Only combine ideas that go together, and only combine the sentences with a semi-colon, or a comma and a coordinating conjunction (FANBOYS).

Now you know the rules of combining sentences and can avoid breaking the English grammar rules of run-on sentences.