Introduction

Every sentence has a subject and a predicate, and missing one of these elements results in a fragment. The subject of a sentence is the noun, pronoun, or phrase or clause the sentence is about, and the predicate is the rest of the sentence after the subject:

Einstein’s general theory of relativity has been subjected to many tests of validity over the years.

In a secure landfill, the soil on top and the cover block storm water intrusion into the landfill. (compound subject)

There are two subjects in this sentence: soil and cover.

Notice that the introductory phrase, “In a secure landfill,” is not a part of the subject or the predicate.

When you’ve tried to overcomplicate a sentence or mold two thoughts into one, you will often end up with a run-on sentence. Adding the correct punctuation will help break these two thoughts into complete sentences.

Comma splices break up two independent clauses. Where a comma was used incorrectly, you would instead use a period or semicolon to represent the two thoughts.

Fragment

Sentence fragments do not include a complete thought; they cannot stand alone. For a sentence to be considered a complete thought, a subject and predicate must be included. 

A sentence cannot simply be written as: 

The glass of juice. (Subject) 

 Or 

Crashed the cruise ship ten years ago. (Predicate) 

Complete thoughts would look like: 

The glass of juice was very expensive. 

Captain Jones crashed the cruise ship ten years ago. 

Let’s take a look at a couple of examples:

Ivana appeared at the committee meeting last week. And made a convincing presentation of her ideas about the new product.

The committee considered her ideas for a new marketing strategy quite powerful. The best ideas that they had heard in years.

She spent a full month evaluating his computer-based instructional materials. Which she eventually sent to her supervisor with the strongest of recommendations.

Let’s look at the phrase “And made a convincing presentation of her ideas about the new product” in example one. It’s just that: a phrase. There is no subject in this phrase, so the easiest fix is to simply delete the period and combine the two statements:

Ivana appeared at the committee meeting last week and made a convincing presentation of her ideas about the new product.

Let’s look at example two. The phrase “the best ideas they had heard in years” is simply a phrase—there is no verb contained in the phrase. By adding “they were” to the beginning of this phrase, we have turned the fragment into an independent clause, which can now stand on its own:

The committee considered her ideas for a new marketing strategy quite powerful; they were the best ideas that they had heard in years.

What about example three? Let’s look at the clause “Which she eventually sent to her supervisor with the strongest of recommendations.” This is a dependent clause; the word which signals this fact. If we change “which she eventually” to “eventually, she,” we also turn the dependent clause into an independent clause.

She spent a full month evaluating his computer-based instructional materials. Eventually, she sent the evaluation to her supervisor with the strongest of recommendations.

Run-on Sentences

A fused sentence is sometimes called a run-on sentence. The concept is simple. If your teacher marks fused sentence or run-on on your paper, it’s because you have put two complete thoughts or independent clauses together without the proper punctuation or any kind of sentence boundary. Here is an example:

There were a thousand zombies cheering for the home team when I walked onto the field I don’t think even one of them noticed me.

 

And, here is the corrected sentence:

There were a thousand zombies cheering for the home team when I walked onto the field; I don’t think even one of them noticed me.

The key is to remember that you must have some kind of boundary between your independent clauses. You can use punctuation, such as the period or the semicolon, or you can use a comma with a coordinating conjunction(and, but, or, for, nor, so, yet).

 

NOTE: A comma alone cannot separate independent clauses. Using a comma to separate independent clauses actually creates a comma splice.

Comma Splices

Many students think a comma splice is just any kind of comma error, but a comma splice is a very specific type of comma error.

A comma splice occurs when you use a comma to separate two independent clauses. A comma is not strong enough to perform this function, which causes the problem. It’s important to remember to use proper punctuation to separate your independent clauses; otherwise, you end up with a sentence like this:

He promised me, if I didn’t report him, he would never do it again, however, the next night, he was back, playing his bagpipes under my balcony.

 

Here, you should notice the only comma error is the one between again and however. The reason this is a comma splice is because the actually begins a new sentence or independent clause, but there is not a proper boundary between these two sentences. Here is how the sentence could be corrected:

He promised me, if I didn’t report him, he would never do it again; however, the next night, he was back, playing his bagpipes under my balcony.

Summary

To review, the two requirements for a thought to be qualified as a complete sentence include having a subject and a predicate.

The subject of a sentence includes the noun.

Marge went to the store. (Marge)

The predicate is the verb and everything after the noun.

Marge went to the store. (went to the store)

Run-on sentences are often created due to combining two thoughts into one sentence. Correcting the punctuation will help you form complete sentences.

I was already late for work and I did not want to be late, however, I really wanted to stop for a donut. (incorrect)

I was already late for work and I did not want to be late; however, I really wanted to stop for a donut. (correct)

Comma splices break up two independent clauses incorrectly with a comma instead of a period or semicolon. Adjusting the punctuation will break your sentence into two complete thoughts.

Disney on ice was a blast, my children enjoyed the show. (incorrect)

Disney on ice was a blast; my children enjoyed the show. (correct)

Sources:

“Basic Patterns and Elements of the Sentence.” By: David McMurrey. Retrieved from: https://www.prismnet.com/~hcexres/textbook/twsent.html. Licensed under: CC-BY

“Comma Splice.” By: Excelsior College Online Writing Lab. Retrieved from: http://owl.excelsior.edu/grammar-essentials/common-errors/common-errors-comma-splice/ Licensed under: CC–BY

“Fragments.” By: David McMurrey. Retrieved from: https://www.prismnet.com/~hcexres/textbook/gram1.html#frag. Licensed under: CC-BY

“Run-on Sentences.” By: Excelsior College Online Writing Lab. Retrieved from: http://owl.excelsior.edu/grammar-essentials/common-errors/common-errors-run-on-sentences/ Licensed under: CC-BY