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Sometimes, when we’re excited or have too much to say, we rush our writing and squeeze two complete thoughts into one sentence without the right punctuation. That’s called a run-on sentence, and it can confuse your reader. These worksheets will help you spot and fix those sentence “traffic jams” so your writing flows clearly and smoothly. Let’s slow down and fix those run-ons together!
Run-On Sentences Worksheets
- Read each sentence carefully. Write “Run-on” if the sentence is incorrect, or “Correct” if it is properly written.
Answer key:
| Sentence | Answer | Explanation |
|---|---|---|
| 1. I tried calling her last night, but she didn’t answer the phone. | Correct | Two clauses joined correctly with a coordinating conjunction (but). |
| 2. The dog barked loudly it scared the neighbors. | Run-on | Two independent clauses joined with no punctuation or conjunction. |
| 3. We went to the museum yesterday it was full of amazing art. | Run-on | Two independent clauses not properly joined. |
| 4. After lunch, we decided to walk through the park. | Correct | Single independent clause. |
| 5. The weather was terrible, we stayed indoors and watched movies. | Run-on | Comma splice (two independent clauses joined by a comma only). |
| 6. I cleaned my room my brother didn’t clean his. | Run-on | No punctuation or conjunction between independent clauses. |
| 7. She enjoys painting, and her artwork is really beautiful. | Correct | Coordinating conjunction (and) used correctly. |
| 8. They traveled to Japan last year they loved the food and culture. | Run-on | Missing punctuation or conjunction. |
| 9. He wanted to go hiking, but it rained the whole weekend. | Correct | Properly joined with but. |
| 10. I have a meeting at 3 PM please don’t be late. | Run-on | Two independent clauses run together without correct punctuation. |
2. Correct the following run-on sentences.
1. Original:
Sophia’s favorite YouTuber posted about starting roller skating, she bought a pair of skates.
Correction:
✅ Sophia’s favorite YouTuber posted about starting roller skating, so she bought a pair of skates.
Explanation:
This is a comma splice (two independent clauses joined only by a comma). We fix it by adding a coordinating conjunction like “so”.
2. Original:
I woke up late this morning I missed the bus and had to walk to school.
Correction:
✅ I woke up late this morning, so I missed the bus and had to walk to school.
Explanation:
Two independent clauses are joined without punctuation. We add a comma and “so” to fix the run-on.
3. Original:
A sliming booth was a big hit at the fall festival, kids paid $1 to dump goop on their favorite teachers.
Correction:
✅ A sliming booth was a big hit at the fall festival. Kids paid $1 to dump goop on their favorite teachers.
Explanation:
This is another comma splice. We correct it with a period and capital letter to separate the two full sentences.
4. Original:
I went to the bookstore to buy a novel I ended up spending an hour browsing through magazines.
Correction:
✅ I went to the bookstore to buy a novel, but I ended up spending an hour browsing through magazines.
Explanation:
These are two complete thoughts with no conjunction or punctuation. Add a comma and “but” to connect them logically.
5. Original:
Jessica enjoys baking cookies she doesn’t like cleaning up the kitchen afterward.
Correction:
✅ Jessica enjoys baking cookies, but she doesn’t like cleaning up the kitchen afterward.
Explanation:
This is a run-on. Add a comma and “but” to join the contrasting ideas properly.
6. Original:
The train was delayed due to bad weather we missed the conference by almost two hours.
Correction:
✅ The train was delayed due to bad weather, so we missed the conference by almost two hours.
Explanation:
Two full sentences are run together. Add a comma and “so” to fix it.
7. Original:
My parents visited us during the holidays they brought lots of food and gifts for everyone.
Correction:
✅ My parents visited us during the holidays, and they brought lots of food and gifts for everyone.
Explanation:
Two independent clauses joined without punctuation. Add a comma and “and” for clarity.
Run-On Sentences Exercises
Exercise 1: Identify the Run-on
Direction:
Read each sentence below. Write “Run-on” if the sentence is incorrect, or “Correct” if the sentence is properly written.
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I love reading mystery novels, they always keep me guessing.
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The baby is sleeping, please lower your voice.
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We took a road trip last summer and visited five different states.
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The movie ended we all sat there in silence.
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Laura baked a cake it smelled delicious.
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He studied hard for the exam, and he passed with flying colors.
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My friends came over we played games all night.
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The phone rang, but no one answered.
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I enjoy painting it helps me relax.
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They left early, so they could catch the train.
Answer Key
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Run-on – comma splice (should use period, semicolon, or conjunction)
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Run-on – comma splice
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Correct – joined with coordinating conjunction (and)
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Run-on – fused sentence (no punctuation or conjunction)
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Run-on – fused sentence
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Correct – correctly joined with and
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Run-on – fused sentence
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Correct – properly joined with but
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Run-on – fused sentence
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Correct – properly joined with so
Exercise 2: Fix the Run-on
Direction:
Read the run-on sentences below and rewrite them correctly using a period, semicolon, or a coordinating conjunction (for, and, nor, but, or, yet, so).
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I was very tired I stayed up late to finish my project.
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The lights went out we had to use candles.
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My brother plays the guitar he’s also learning the piano.
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The test was difficult many students failed it.
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We missed the train we had to wait for the next one.
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I like science class I don’t enjoy math.
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She was nervous about her speech she practiced all night.
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It rained heavily the soccer match was canceled.
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Tom is allergic to cats he has two of them at home.
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They forgot their tickets they couldn’t enter the concert.
Answer Key
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I was very tired, but I stayed up late to finish my project.
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The lights went out, so we had to use candles.
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My brother plays the guitar, and he’s also learning the piano.
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The test was difficult; many students failed it.
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We missed the train. We had to wait for the next one.
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I like science class, but I don’t enjoy math.
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She was nervous about her speech, so she practiced all night.
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It rained heavily, so the soccer match was canceled.
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Tom is allergic to cats, yet he has two of them at home.
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They forgot their tickets, so they couldn’t enter the concert.
Exercise 3: Multiple Choice Correction
Direction:
Each sentence below contains one correct version. Choose the correct sentence from the options a, b, c, or d.
a. I ran to the store it was about to close.
b. I ran to the store. It was about to close.
c. I ran to the store, it was about to close.
d. I ran to the store and it was about to close.
a. She loves cooking she rarely has time for it.
b. She loves cooking, but she rarely has time for it.
c. She loves cooking; but she rarely has time for it.
d. She loves cooking, she rarely has time for it.
a. We were hungry we ordered pizza.
b. We were hungry, so we ordered pizza.
c. We were hungry and we ordered pizza.
d. We were hungry. So, we ordered pizza.
a. The dog barked loudly, everyone woke up.
b. The dog barked loudly and everyone woke up.
c. The dog barked loudly. Everyone woke up.
d. The dog barked loudly; and everyone woke up.
a. I finished my homework I watched a movie.
b. I finished my homework, I watched a movie.
c. I finished my homework, so I watched a movie.
d. I finished my homework; so I watched a movie.
Answer Key
| # | Correct Answer | Explanation |
|---|---|---|
| 1 | b | Two independent clauses joined correctly with a period. |
| 2 | b | Proper use of comma + but to connect two contrasting ideas. |
| 3 | b | Correct use of comma + so for cause and effect. |
| 4 | c | Period correctly separates two independent sentences. |
| 5 | c | So with a comma properly connects the clauses. |
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