What is a comma splice?

Two complete sentences joined by only a comma: 'We won, everyone cheered.' It shows up in the multiple-choice items as a tempting wrong answer, because it is the run-on fourth graders write most often.

Which standard is this?

L.4.1.f, the same standard as sentence fragments: produce complete sentences, recognizing and correcting fragments and run-ons. The two pages make a natural pair.

4th grade run-on sentences

4th grade run-on sentences worksheets

Fourth grade run-on worksheets practice L.4.1.f directly: recognize and correct run-ons. The run-ons get longer, and the errors to catch now include the comma splice, two sentences joined by a bare comma, which is the error fourth graders write most.

Free printable PDF worksheet, aligned to Common Core L.4.1.f.

Each print is a different sheet with its own answer key. You don't need to sign up.

The kind of sentences you'll fix

Each line runs two sentences together. Add the missing period and capital letter to split them.

The goalie dove left the ball bounced in anyway.
Fixed: The goalie dove left. The ball bounced in anyway.
The frog leaped off the rock it splashed into the pond.
The moon rose early it looked huge and orange.

Every print pulls a new set of sentences at this level, so a make-up test or a second sibling gets a different mix.

What's on a 4th grade sheet

4th grade sheets draw from 60 sentences, 8 to a page. 3rd and 4th grade print from the same 60 sentences. The teaching notes below are written for this grade.

A few of the sentences, as the answer key corrects them:

My brother tripped. His books went flying.
The train whistled. It slowed at the crossing.
Nia practiced her lines. She said them perfectly.

Fix it. Each line runs two sentences together. Add the missing period and capital letter to split them. 8 sentences to fix per page.
Choose the sentence. Circle the letter of the correctly punctuated sentence. 8 questions per page.

Every version prints on US Letter or A4, with its answer key on the last page.

How to teach this

Name the comma splice this year. Kids feel virtuous for using a comma, so show them the test: read each half alone. If both halves stand as sentences, a comma alone is not strong enough to hold them. Period, or comma plus and, but, so.

Watch for: Kids split at the first breath instead of the end of the idea. Have them find the two parts that could each stand alone as a sentence; the split goes where the second one starts. A part that opens with when, because, or if can't stand alone, so it stays attached to the sentence after it. Kids think a comma fixes a run-on. A comma alone makes a comma splice, which is still a run-on wearing a disguise. It needs a period or a comma plus a joining word.

Common questions about 4th grade run-on sentences

What is a comma splice?: Two complete sentences joined by only a comma: 'We won, everyone cheered.' It shows up in the multiple-choice items as a tempting wrong answer, because it is the run-on fourth graders write most often.
Which standard is this?: L.4.1.f, the same standard as sentence fragments: produce complete sentences, recognizing and correcting fragments and run-ons. The two pages make a natural pair.

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Aligned to Common Core L.4.1.f. Reviewed by the One more sheet team. Content version 241, updated October 2026.

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