How to help your child fix run-on sentences

To fix a run-on sentence, help your child find complete thoughts that have been pushed together without a suitable join. Start by separating them with full stops. Once those boundaries are clear, show how a word such as but or because can explain the relationship between ideas.

Understand the idea

A run-on sentence is not simply a long sentence. A short sentence can have the problem: "I waved she smiled." Both I waved and she smiled can stand alone, but nothing joins or separates them.

Say, "Tell me who this part is about and what happened. Could that part be a sentence by itself?" This introduces the idea of an independent clause without making the term the main task.

A comma alone usually cannot join two complete clauses in ordinary school writing. "I waved, she smiled" has a comma splice. Your child can repair it with a full stop or a suitable joining word.

Reading aloud helps children notice where ideas change, but a breath is not a reliable punctuation rule. Readers pause in different places. Check the meaning and sentence structure as well as the sound.

See it worked through

We missed the bus. We walked home.

We missed the bus, so we walked home.

A full stop or a suitable joining word can show how the thoughts fit.

Repair the join, then choose the meaning

Draft: The gate was locked we used the side entrance.

First find the complete thoughts: The gate was locked and we used the side entrance.

One repair is: The gate was locked. We used the side entrance. Both sentences now have a clear boundary.

Another is: The gate was locked, so we used the side entrance. The word so shows that the locked gate led to the choice of entrance.

You can also write: We used the side entrance because the gate was locked. Here, because introduces the reason. The words because the gate was locked depend on the rest of the sentence.

Ask, "Which version explains why they used the other entrance?" Your child should notice that punctuation repairs the boundary, while joining words can add a relationship.

Try it together

A ten-minute sentence repair shop

Read these drafts aloud together. For each one, draw a line where one complete thought ends and the next begins.

1. The toast burned I made some porridge.
2. Zoe wanted to play outside the rain was too heavy.
3. My pencil snapped, I borrowed another one.

First repair each draft with full stops. Then choose a joining word that shows how the ideas relate. Read both versions and ask your child which one best expresses the meaning.

Check the answer

One set of repairs is:

1. "The toast burned. I made some porridge." Or "The toast burned, so I made some porridge." So suggests the porridge was a response to the burned toast.
2. "Zoe wanted to play outside. The rain was too heavy." Or "Zoe wanted to play outside, but the rain was too heavy." But shows a contrast between her wish and the obstacle.
3. "My pencil snapped. I borrowed another one." Or "My pencil snapped, so I borrowed another one." The comma alone in the draft was not enough.

Other sensible repairs are possible. Check that the joining word matches the meaning.

Check their understanding

Offer "The cat slept on the chair while we ate lunch." Ask whether it needs splitting. It is already a complete, correctly joined sentence. While we ate lunch gives timing information and depends on the main clause.

Then offer "The cat slept on the chair we ate lunch." Ask your child to repair it and explain the change. This comparison checks whether they understand the join rather than assuming that every sentence with two actions is wrong.

Make it easier or harder

Make it easier with two short clauses and full stops only. Supply the capital letters after your child chooses the boundaries.

Make it harder with a short paragraph from their own writing. Ask them to fix one run-on, then choose a joining word that preserves their intended meaning. Leave semicolons for later if sentence boundaries still need practice.

Teaching notes

The Australian Government Style Manual's guidance on clauses explains main clauses, dependent clauses and compound sentences. This activity applies that distinction to original editing examples rather than treating sentence length as the problem.

Spelling, grammar and punctuation practice

Practise spelling, grammar and punctuation in context, then talk through the answers together.

Create a free account↗Browse student study guides

The platform is currently free. Create a parent account, then add your child to get started.