This short video will help you understand and avoid one of the most common grammatical mistakes, the error of comma splice and run-ons on GMAT
Comma Splices and Run-Ons on GMAT
A bit of good news to begin this article with, you will not have to understand comma splices and run-on sentences separately. If you understand one concept, the other will come to you naturally. Let us begin by taking a look at the following sentence:
Professor entered the class, the students were waiting.
Can you see what is wrong with this sentence? It has a comma splice error. If you could not identify the error, do not worry; in this short article that is precisely what we shall be discussing.
What is Comma Splice?
The error of comma splice occurs when two independent clauses are joined using a comma. The comma is considered too weak a punctuation to join two independent clauses. Let us illustrate through a few examples.
Example 1 - Professor entered the class, students were waiting.
You see, these are two independent thoughts that can quite stand on their own. Both "Professor entered the class" and "students are waiting" are complete sentences in and of themselves and, thus, are independent clauses that cannot be joined by a comma.
Example 2 - Jack has great soccer skills, he is a great team man.
Once again, we see that the two parts of the sentence, "Jack has great soccer skills" and "he is a great team man" are complete sentences. Thus, they too cannot be joined by a comma, and this sentence suffers from the error of comma splice.
Example 3 - Henry is conscious about his fitness, he swims every day.
We see the comma splice error here as well. "Henry is conscious about his fitness" is a complete thought, as is "he swims every day."
At this point, we would like to deliver an informal note on the nature of comma splice errors. Even beyond the GMAT, the comma splice is one of the most common writing errors, and tends to happen when we try to write "by the ear". This is because we tend to write based on what we hear and insert a comma wherever we think there needs to be a pause, even where technically, grammatically, and logically speaking there should not be. Grammar is a lot more sophisticated.
How to Correct the Comma Splice
There are three main ways to correct the comma splice error.
1. The first way is to replace the comma with a semicolon. A period can also be used if the split between the clauses is well-defined enough.
For example, in the sentence Professor entered the class, students were waiting.
, we can simply replace the comma with a semicolon and it will be all right, as the semicolon is strong enough to join independent clauses. Furthermore, replacing the comma with a period to create two separate sentences would also be grammatically correct, but before doing so we must consider the meaning of the sentence. In this sentence, there is an interdependence between the two parts, so a semicolon is a better option.
The correct sentence will read Professor entered the class; the students were waiting
2. The second way of correcting this error is by adding a coordinating conjunction after the comma. The most common conjunctions are and, or, for, so, but, yet, and nor.
Let's take an example, Jack has great soccer skills, he is a great team man.
Here, the sentence can be corrected by adding a conjunction after the comma. A conjunction combined with a comma is strong enough to join two independent clauses.
One form of the correct sentence can be Jack is a great football player, and he is a great team man.
Depending on the meaning, other conjunctions can be used as well.
3. The third way to correct this error is by adding subordinating conjunction, such as because, when, since, as, etc. What this does is turn one of the two independent clauses into a dependent clause. For example, Henry is conscious about his fitness, he swims every day.
is an incorrect sentence, but is the subordinating conjunction "because" is used to form the sentence "Because Henry is conscious about his health, he swims every day." it will be correct. "Because Henry..." is not an independent clause, it is a dependent clause, and a comma is strong enough to join an independent clause with a dependent clause.
Another version of this sentence can be Henry swims every day when he is conscious about his fitness.
Here the second clause is made into the dependent clause, meaning that the comma is not needed at all.
What is Run-On?
As mentioned earlier, the run-on error will not take long to address. The Run-on error occurs when two independent clauses are connected without punctuation or conjunction. As you can see in all the examples of the comma splice error that we looked at, a comma was used to join independent clauses.
Professor entered the class, students were waiting.
Jack has great soccer skills, he is a great team man.
Henry is conscious about his fitness, he swims every day.
The error of run-on is far more basic. In this error, you would not even have a comma.
Professor entered the class students were waiting.
Jack has great soccer skills he is a great team man.
Henry is conscious about his fitness he swims every day.
Thus, we can say that the run-on is a more severe form of the comma splice. Where a comma splice has insufficiently strong punctuation, the run-on has none. As such, the run-on error can be corrected using the same methods for correcting comma splice errors.
This article has deliberately been kept brief; for a more elaborate explanation, please refer to Experts' Global's Stage One Sentence Correction videos.