Run-on Sentences and Sentence Fragments

There are two common ways in which we write improper sentences.  Improper sentences include run-on sentences and sentence fragments. These are easy to remember because of their names! Run-on sentences run on and on and look like a bunch of sentences mashed into one. Fragments are literally pieces of sentences; they are not complete sentences, but they are trying to stand alone. Run-ons that go on forever are easy to identify.  It's also easy to find fragments that are missing most of the sentence.  However, there are run-ons and fragments that look a lot like complete sentences and slip under the radar.  The following rules will help you find them!

Vocabulary: 

An independent clause is a phrase that can stand alone as a complete sentence.  An independent clause only requires a subject and a verb.  To be an independent clause a phrase must have at least a subject and a verb.

  • “Dogs run.” is an independent clause and therefore a complete sentence. 
  • “Dogs pant.” is also an independent clause and therefore a complete sentence. 
  • “Dogs run, dogs pant.” is a run-on sentence because it combines two independent clauses with just a comma. 

Independent clauses may be joined by a conjunction or a semicolon, but NOT by a comma.  When independent clauses are joined by a comma, it’s a run-on sentence (AKA a comma splice).

Correct this in any of the following ways:

"Dogs run; dogs pant."  You may combine independent clauses with a semicolon.

"Dogs run, and dogs pant." You may combine independent clauses with a coordinating conjunction (a FANBOYS) and a comma.

"When dogs run, dogs pant." You may use a subordinating conjunction to make one clause a dependent clause.

  • “When dogs run,” is a not an independent clause (it is a dependent clause and thus a sentence fragment) because, while it has a subject and a verb, it also contains a subordinating conjunction, which makes this phrase require another phrase to make it a complete sentence. 

A subject and verb modified with a preposition becomes a dependent clause.  A dependent clause is NOT an independent clause.

Dependent clauses, standing alone, are sentence fragments.  For instance, “When dogs run” is a dependent clause.  Alone, it is NOT is not a complete sentence, it is a sentence fragment.

However, you can join a dependent clause and an independent clause with a comma for a single complete sentence.  “When dogs run, dogs pant.” is a complete sentence and not a run-on.

Example: When the worst of the battle had been completed and won by the British, the soldiers retreated to the camps that they had made the night before.

The word “When” saves this sentence from being a run-on.

 

How can you tell if a sentence is a run-on or a fragment?

Let’s try the following example:

Los Angeles Animal Services has instructions to keep animals alive as long as possible; it tries to make sure that dogs are suitable for placement, trainers work with dogs for several weeks when dogs exhibit signs of aggressiveness.

In each sentence, underline subjects and the verbs in each clause.

Los Angeles Animal Services has instructions to keep animals alive as long as possible; it tries to make sure that dogs are suitable for placement, trainers work with dogs for several weeks when dogs exhibit signs of aggressiveness.

Each subject/predicate pair should be:

  • Connected with a conjunction (e.g., for, and, nor,  but, or, yet, so) or semi-colon OR
  • One of the clauses should be combined with a word that makes it a dependent clause (e.g., since, when because, even though, etc.)

Los Angeles Animal Services and has: Independent clause, separated from next clause with semi-colon. Correct.

it and tries  : Independent clause, separated from prior clause with semi-colon. Correct.

trainers and work : Independent clause, separated from prior independent clause with comma.  Wrong.

dogs and exhibit: "when" makes this a dependent clause so this can be added to the end of an independent clause. Correct.

 

 

 

Practice Problems:

  • Run-on Sentences and Sentence Fragments Practice

    Read the following sentences.  If the sentence is a fragment, add a subject or verb, or remove a subordinating conjunction to make it a complete sentence.

    1. Rabbits jump.
    2. If you know me.
    3. When there is a full moon and the sun is starting to set later in the day.
    4. The most magnificent and ripest apples in the world.
    5. Aliens are terrifying.
    6. Even though I hate to go to the library.
    7. Although algebra is supposed to be critical for learning more advanced math skills. 
    8. The turtle always seems to beat the hare in the race.
    9. While Goldilocks seems to be far too picky to be a sympathetic character.
    10. Hoping to win an Olympic medal.

    Read the following sentences.  If the sentence is a run-on, add a comma or a semicolon or a colon to make it a correct sentence.

    1. When you sign up for AP classes, even if you think that they will be easy, you are making a commitment to work hard.
    2. Everyone knows that UCLA and USC have a long-standing rivalry, I know who I am rooting for.
    3. If you decide to be a Trojan, you have to accept that Bruins will think you are spoiled.
    4. Some people choose to go to UCLA, others think that they make the wrong decision.
    5. Water Polo is a popular high school sport in Southern California, though high schools without pools have a hard time competing.
    6. I wonder why, if all kids are supposed to get equal educations, it's fair for some schools to have pools while others do not. 
    7. Our rival school has a pool, I'm a little jealous.
    8. I know that if we had a pool, I'd be on the swim team, even though morning workouts would be rough.
    9. Venice high school has a pool, but I hear that the roof is caving in.
    10. I would be scared to swim in building with a broken roof, I'll pass on a pool if that's the kind of pool it's going to have.

    Answer Key:

  • Run-on Sentences and Sentence Fragments

    If the sentences below are run-ons or fragments, correct them by adding/removing/changing words or punctuation marks. (Note: some sentences are correct!)

    Basic:

    1. The dogs run, they are very fast.
    2. When apples fall from trees in the fall.
    3. While I hope that I will get into a great college after high school.
    4. Even though rats and mice look very similar, they are actually difference species,
    5. Schools are supposed to teach children academics, they are also expected to teach character lessons.
    6. Teachers have to control a room, and they need to inspire students to learn.

    Advanced:

    1. Many psychologists do not use hypnosis in their practices, it is because they know very little about it and are wary of it as a result. 
    2. Since the novels of Elizabeth Phelps are less well known today than many of her contemporaries' works, one is surprised to learn that she was once a best-selling author. 
    3. Even the film’s most heroic characters are played with straightforward realism, this restraint results in a very powerful story. 
    4. Although gale-force winds often pass through the Eiffel Tower, causing it to sway no more than four inches. 
    5. Even though the chain was supposed to be strong enough to lift 50 tons. 
    6. Although for many years, television was people's primary mode of viewing and despite the fact that streaming is now catching up with network and cable provided viewing.



     

    Answer Key:

Test Prep Practice

  • Run-on Sentences and Sentence Fragments Test Prep

     

    $\boxed 1$ Although it is a crazy time of year: college application season.  Across the country, seniors have to figure out their $\boxed 2$ futures, they ponder so many huge decisions . Do they want to go to a big college or small college? Are they looking for a big name school or a more personalized college experience?  $\boxed 3$Do they want to stay in state or do they want to move out of state? Are they Ivy League material?

    $\boxed 4$ Once students figure out where they want to apply, the work begins. College applications require a laundry list of $\boxed 5$ materials. Essays, SAT scores, transcripts, and resumes. And don't even get seniors started on that "brag sheet" that they are supposed to write. $\boxed 6$ If you think teens like to talk about themselves. Just try  to get them to fill out a list of all of their accomplishments. $\boxed 7$They hate it.

     

    $\boxed 8$ The idea is that, through a combination of essays and scores and grades, students can show every facet of themselves on a college application, and hopefully they will look good enough for admission to their dream schools. But, anyone who has ever tried to cram their essence into a online form knows that it's just not as easy as $\boxed 9$ it sounds. Even for the best students. Even stellar students need to carefully choose essay topics and finesse their activities to make them look as good as possible. $\boxed {10}$  For the average student, who may not have a list of amazing accomplishments, the daunting process. And yet, each year, thousands of students submit tens of thousands of applications, and cross their fingers and wait.

    $\boxed {11}$ Once admissions letters start to come out and the waiting is over. But for some students, this is precisely when the most difficult part of the process $\boxed {12}$ begins, they must choose.  Students will consider financial aid packages, take campus tours, scour message boards, and wrack their brains until that fateful day in may when they must make a choice.  That choice will determine where they spend the next four years. 

     

    1. 

    1. NO CHANGE
    2. Although it is a crazy time of year; college application season.
    3. Although college application season is a crazy time of year.
    4. It is a crazy time of year: college application season.

    2. 

    1. NO CHANGE
    2. futures they ponder
    3. futures, pondering
    4. futures. Pondering

    3. 

    1. NO CHANGE
    2. Do they want to stay in state or move out of state?
    3. Do they want to stay in state or? Do they want to move out of state?
    4. Do they want to stay in state or do they think they prefer to move out of state?

    4. 

    1. NO CHANGE
    2. Once students figure out where they want to apply the work begins.
    3. Students figure out where they want to apply, the work begins
    4. Once students figure out where they want to apply. The work begins.

    5. 

    1. NO CHANGE
    2. materials: essays, SAT scores, transcripts, and resumes.
    3. materials, they need essays, SAT scores, transcripts, and resumes.
    4. materials. Like essays, SAT scores, transcripts, and resumes. 

    6. 

    1. NO CHANGE
    2. If you think teens like to talk about themselves, so just try
    3. If you think teens like to talk about themselves, just try
    4. If you think teens like to talk about themselves: just try

     

    7. 

    1. NO CHANGE
    2. They will always be hating it. 
    3. Although they hate it. 
    4. Even though they hate it. 

     

    8. 

    1. NO CHANGE
    2. The idea is that, through a combination of essays and scores and grades. Students can show every facet of themselves on a college application.  Hopefully they will look good enough for admission to their dream schools. 
    3. The idea is that students can show every facet of themselves on a college application.  Through a combinations of essays and scores. Hopefully they will look good enough for admission to their dream schools. 
    4. The idea is that, hopefully they will look good enough for admission to their dream schools. Through a combination of essays, scores, and grades.

    9. 

    1. NO CHANGE
    2. it sounds. Not even for the best students.
    3. it sounds for the best students.
    4. it sounds, even for the best students.

    10.

    1. NO CHANGE
    2. For the average student the process is daunting, who may not have a list of amazing accomplishments.
    3. For the average student, who may not have a list of amazing accomplishments, it's a daunting process.  
    4. For the average student, who may not have a list of amazing accomplishments, the process daunts.  

    11. 

    1. NO CHANGE
    2. Once admissions letters start to come out, the waiting is over.
    3. Once admissions letters start to come out. Waiting stops.
    4. Finally, admissions letters start to come out, the waiting is over.
    12.
    1. NO CHANGE
    2. begins, they choose.
    3. begins, because they must choose.
    4. begins. Because they must choose.
     
     

    Answer Key:

Skill: