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 wrong choices 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.

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The kind of sentences you'll fix

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

  1. The race started the crowd cheered loudly.

    Fixed: The race started. The crowd cheered loudly.

  2. Grandma called we talked for an hour.
  3. The frog leaped off the rock it splashed into the pond.

Every print pulls a fresh set of sentences at this level, so a make-up test or a second sibling never gets the same sheet.

What's on each sheet

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 second who-did-what pair; the split goes right before 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 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 178, updated August 2026.

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