Run-on Sentences and Coma Splices

Run-on Sentences and Comma Splices
Two very common errors among writers are run-on sentences and comma splices. Amazingly, both of these errors are caused by not knowing what a sentence is.
A sentence is a group of words containing a subject and verb (also known as a clause) that expresses a complete thought. A sentence can also be called an independent clause: clause because it contains a subject and a verb, and independent because it can stand alone.
Let’s look at some examples of this type of construction.
Independent clauses/sentences: The doorbell rang. I was on my way to work. I like going to school. It’s difficult to balance my responsibilities.
A run-on sentence occurs when 2 sentences are placed together with no punctuation between them. Normally, a period would be placed between them (although there are other ways to correct the error, which we’ll discuss a little later in the lesson).
A comma splice occurs when a comma is mistakenly placed between the 2 sentences.
Run-on sentences: The doorbell rang I was on my way to work. I like going to school it’s difficult to balance my responsibilities.
Comma splices: The doorbell rang, I was on my way to work. I like going to school, it’s difficult to balance my responsibilities.
Correcting both types of errors is simple.
One solution is to place a period between the sentences. The doorbell rang. I was on my way to work. I like going to school. It’s difficult to balance my responsibilities.
A second solution is to place a semicolon between the sentences. The semicolon lets the reader know that the sentences are connected in their idea. The doorbell rang; I was on my way to work. I like going to school; it’s difficult to balance my responsibilities.
Semicolons are often used with a special type of word called conjunctive adverbs. These words come at the beginning of the second sentence and indicate the connection between the ideas in the sentences. Conjunctive adverbs are words like however, therefore, nevertheless, as a result, consequently, then, now, next, and similarly. If a conjunctive adverb has more than one syllable, it must have a comma after it. The doorbell rang; however, I was on my way to work. I like going to school; nevertheless, it’s difficult to balance my responsibilities.
A third solution for correcting run-on sentences and comma splices is to place a coordinating conjunction and a comma between the sentences. Coordinating conjunctions are but, or, yet, so, for, nor, and and (which you can memorize as BOYSFAN). These are the only words that can join two sentences using merely a comma. The doorbell rang, but I was on my way to work. I like going to school, yet it’s difficult to balance my responsibilities.
There is one other way to correct run-on sentences and comma splices. This solution requires changing one of the independent clauses to a dependent clause before joining the sentences. A dependent clause is a group of words that contains a subject and a verb but doesn’t express a complete thought, so it can’t stand alone; in other words, it can’t be punctuated like a sentence. To create a dependent clause, add a subordinating conjunction (such as when, if, although, because, since, or while) to the beginning of a sentence. The sentence is no longer a sentence/independent clause; now it is a dependent clause and must be joined to a sentence/independent clause to make a new sentence.
When the dependent clause begins the sentence, it must be followed by a comma. When I was on my way to work, the doorbell rang. Although I like going to school, it’s difficult to balance my responsibilities.
If the independent clause begins the sentence, there is not a comma between it and the following dependent clause. I was on my way to work when the doorbell rang. I like going to school although it’s difficult to balance my responsibilities.
To summarize, there are six correct options for combining sentences:

1) Independent clause. Independent clause. (2 independent clauses as 2 separate sentences) The boy hit the dog. The dog bit the boy. Mary called Joe. He asked her for a date.
2) Independent clause; independent clause. (2 independent clauses joined by a semicolon) The boy hit the dog; the dog bit the boy. Mary called Joe; he asked her for a date.
3) Independent clause; ca, independent clause. (2 independent clauses joined by a semicolon and a conjunctive adverb) The boy hit the dog; as a result, the dog bit the boy. Mary called Joe; consequently, he asked her for a date.
4) Independent clause, cc independent clause. (2 independent clauses joined by a comma and a coordinating conjunction – a BOYSFAN word) The boy hit the dog, so the dog bit the boy. Mary called Joe, and he asked her for a date.
5) Dependent clause, independent clause. (a dependent clause followed by a comma and an independent clause) After the boy hit the dog, the dog bit the boy. When Mary called Joe, he asked her for a date.
6) Independent clause dependent clause. (an independent clause followed by a dependent clause) The boy hit the dog before the dog bit the boy. Mary called Joe after he asked her for a date.
Learning these options will help you avoid writing run-on sentences and comma splices.