B. Foundations of Language · Spelling, Grammar and PunctuationFixing Fragments, Run-ons and Comma Splices
B3.1 D2.6About 40 minutes
Learning goals- I can find sentence fragments, including dependent clauses and -ing phrases standing alone.
- I can find run-on sentences and comma splices.
- I can fix run-ons and comma splices in four different ways.
- I can choose the fix that makes my meaning clearest.
Words to know
sentence fragment
A group of words punctuated like a sentence but missing a subject, a verb, or a complete thought.
run-on sentence
Two or more sentences squished together with no punctuation between them.
comma splice
Two sentences joined with only a comma, and no joining word.
semicolon
A punctuation mark ( ; ) that can join two closely related sentences.
complete thought
An idea that makes sense on its own.
Remember from Grade 4
In Grade 4 you learned that a fragment is only part of a sentence (Because it was snowing.) and a run-on squishes two sentences together (It was cold we wore mitts.).
In Grade 5, your sentences are longer, so these mistakes can hide better! You'll learn to spot a sneaky run-on called a comma splice, and you'll learn four ways to fix run-ons.
Three kinds of fragments
A sentence needs a subject, a verb and a complete thought. Fragments are missing one of these:
- Dependent clause alone: Although the bus was late. (What happened? The thought isn't complete.)
- -ing or -ed phrase alone: Running to catch the bus. / Covered in snow. (Who? There's no subject and no complete verb.)
- Missing subject: Grabbed my backpack and left. (Who grabbed it?)
Fixes: attach it to a nearby sentence, or add what's missing.
- Although the bus was late, we got to school on time.
- Running to catch the bus, I slipped on the ice.
- I grabbed my backpack and left.
The walk-in test
Read your sentence on its own, as if someone just walked into the room and said it. Although the bus was late. Would they understand? No: they'd ask "...and then what?" That's a fragment.
Run-ons and comma splices
A run-on has two complete sentences and nothing between them:
The power went out we lit candles.
A comma splice has two complete sentences joined with only a comma:
The power went out, we lit candles.
A comma alone isn't strong enough to hold two sentences together. Think of it like trying to join two train cars with a piece of tape!
| Fix | How | Example |
|---|
| 1. Period | Split it into two sentences. | The power went out. We lit candles. |
| 2. Comma + FANBOYS | Add a joining word after the comma: for, and, nor, but, or, yet, so. | The power went out, so we lit candles. |
| 3. Subordinating conjunction | Make one part a dependent clause with when, because, after, since... | When the power went out, we lit candles. |
| 4. Semicolon | Use ; between two closely related sentences. | The power went out; we lit candles. |
Worked exampleLet's fix a comma splice
Fix: My cousin lives in Iqaluit, she sent me a photo of the northern lights.
- Check each side of the comma. My cousin lives in Iqaluit is a complete sentence. she sent me a photo of the northern lights is a complete sentence too.
- Two sentences + only a comma = comma splice.
- Choose a fix. The ideas are connected, so try a dependent clause: My cousin, who lives in Iqaluit, or try a period.
My cousin lives in Iqaluit. She sent me a photo of the northern lights. (Or: My cousin lives in Iqaluit, and she sent me a photo of the northern lights.)
Worked exampleLet's fix a fragment
Fix: We stayed inside all afternoon. Because the wind chill was −30.
- Because the wind chill was −30. starts with because. It's a dependent clause standing alone, so it's a fragment.
- Attach it to the sentence before it. When the dependent clause comes at the end, you usually don't need a comma.
We stayed inside all afternoon because the wind chill was −30.
Which fix should I choose?
- Use a period when the ideas are separate, or your sentence is already long.
- Use comma + FANBOYS to show a simple link: and (adding), but (contrast), so (result).
- Use a subordinating conjunction to show time or cause clearly: because, when, after.
- Use a semicolon only when the two sentences are very closely related and similar in importance. Don't overuse it!
Just for funA fragment walks into the library.
And then...?
(That's the whole joke. It's a fragment!)
Hands-on activitySentence surgery
You need: a piece of your own writing (or a page from a book), a pencil, and two colours of pencil or highlighter.
- Ask a grown-up to write 5 sentences with mistakes on a sheet: some fragments, some run-ons, some comma splices, and 1 or 2 that are correct. (Ideas: Skating on the canal. / The puck slid across the ice it hit the boards.)
- With one colour, underline every subject + verb pair you find.
- With the other colour, mark each sentence: F (fragment), R (run-on), CS (comma splice), or ✓ (correct).
- Fix each one, and try to use all four run-on fixes at least once.
- Now check a page of your own writing for the same mistakes.
Your turn
1Fragment, run-on, comma splice or correct? The snowplow came by, it buried our driveway.
Comma splice. Fix: The snowplow came by, and it buried our driveway.
2Fragment, run-on, comma splice or correct? Hoping for a snow day.
Fragment (no subject or complete verb). Fix: We were hoping for a snow day.
3Fragment, run-on, comma splice or correct? The geese honked they flew south.
Run-on. Fix: The geese honked. They flew south. or The geese honked as they flew south.
4Fragment, run-on, comma splice or correct? Although we were tired, we finished the hike.
Correct (dependent clause + independent clause).
5Fix using a FANBOYS word: I wanted to play outside, it was raining.
I wanted to play outside, but it was raining.
6Fix using a subordinating conjunction: We ate supper. Then we washed the dishes. (Combine into one sentence.)
After we ate supper, we washed the dishes.
7Fix using a semicolon: The library was quiet, everyone was reading.
The library was quiet; everyone was reading.
More practice: warm-up
1What three things does a complete sentence need?
A subject, a verb and a complete thought.
Two sentences joined with only a comma.
3Is When the movie ended. a sentence or a fragment?
Fragment (a dependent clause alone).
for, and, nor, but, or, yet, so.
5What punctuation mark is this: ;
More practice: on your own
1Fix the fragment by attaching it: My brother laughed. Covered in maple syrup.
My brother laughed, covered in maple syrup. or Covered in maple syrup, my brother laughed.
2Fix the run-on in two different ways: Our class went to the museum we saw a dinosaur skeleton.
Any two: ...the museum. We saw... / ...the museum, and we saw... / When our class went to the museum, we saw... / ...the museum; we saw...
3Is this a comma splice? After school, we went to the arena. Explain.
No. After school is a phrase, not a sentence. There's only one complete sentence, so the comma is fine.
4Fix: Grabbed my skates. Ran to the rink.
Add a subject and combine: I grabbed my skates and ran to the rink.
5Which fix shows cause most clearly? The road was icy, the bus was late.
A subordinating conjunction: Because the road was icy, the bus was late. (or ..., so the bus was late.)
Challenge
1Edit this paragraph. Fix all fragments, run-ons and comma splices. Last weekend we went to a sugar bush. The sap dripped into buckets. Then it was boiled for hours, the steam smelled sweet. Because it takes about 40 litres of sap to make 1 litre of syrup. Maple syrup is expensive.
Example: Last weekend we went to a sugar bush. The sap dripped into buckets. Then it was boiled for hours, and the steam smelled sweet. Because it takes about 40 litres of sap to make 1 litre of syrup, maple syrup is expensive. Fixes: the comma splice (hours, the steam) gets and; the fragment (Because it takes...) is joined to the last sentence.
2Explain why this is a run-on even though it's short: I ran I fell.
It has two complete sentences (I ran and I fell), each with a subject and verb, and nothing between them. Length doesn't matter. Fix: I ran, and I fell. or I ran. I fell.
3Sometimes writers use a fragment on purpose, like Silence. in a story. When might that be okay, and when should you avoid it?
In stories or ads, an author may use a short fragment on purpose for drama or emphasis, especially in dialogue. Avoid fragments in reports, letters and other formal writing, and only use one on purpose when you can explain why.
Quiz
3. Which correctly fixes The bell rang we went inside?
4. Which sentence uses a semicolon correctly?
5. Which is a complete sentence?
6. Which fix for a run-on adds a dependent clause?
Big idea (B3.1, D2.6): Grade 5 students correct sentence fragments and run-on sentences, and edit their drafts for grammar and punctuation. Comma splices are a very common kind of run-on at this age, because children know commas mark pauses but not that a comma alone can't join two sentences.
How to help at home:
- When your child edits, ask them to read each sentence on its own. Does it stand up by itself?
- Point at a comma and ask: "Is there a full sentence on both sides? Then you need a joining word, a period or a semicolon."
- Praise variety: using different fixes makes writing more interesting.
Common difficulties:
- Starting a sentence with Because and stopping there. It's fine to start with because, as long as an independent clause follows.
- Fixing a comma splice by adding more commas.
- Semicolon overuse after it's first learned. Encourage periods for most cases.
- Fragments in stories can be a deliberate style choice; in reports they're errors.