Inner Growth, Outer Shine

Navigating the world of learning and professional development

Written by Maria Samsonova
on October 14, 2022

A run-on sentence is a common mistake in writing. It is a sentence that is too long. Run-on sentences have too many ideas and too many subjects. This lesson shows you how to avoid or fix run-on sentences.

Here is an example of a run-on sentence:

  • I went to the beach yesterday it was very hot.

“I went to the beach yesterday” is one idea. “It was very hot” is another idea. This sentence has two ideas. It is too long. The correct version is two sentences:

  • I went to the beach yesterday. It was very hot.

Run-on sentences are not grammatically correct. They are also difficult to read. People can’t follow your writing when you keep adding ideas to your sentences. To avoid run-on sentences, follow this rule:

A sentence has got one subject and one main idea.

What does that rule mean? Let’s take a look.

First, your sentences should have one subject. Look at the example with the two subjects underlined:

  • I went to the beach yesterday it was very hot.

This sentence has two subjects. That’s why it is a run-on sentence. It is also talking about two ideas: the action of going to the beach and the weather.

Take a look at some more run-on sentence mistakes:

  • The boy has three sisters and he lives in a large house.
  • Susan works on Saturday, she does not work on Sunday.

You might be thinking that “Susan” and “she” are the same subject. Well, not quite. They are talking about the same person, but when you use “she” you have created a new subject.

Comma Splices

A comma splice is the most common type of run-on sentence. This is when two different ideas are joined by a comma. This is a mistake.

Here is an example:

  • I bought milk, it was expensive.

That is a comma splice, and it is incorrect. Many people think they can use a comma because the ideas are related. That’s not true. If you use a new subject, you need a new sentence.

Solutions to Run-On Sentences

  1. Use a full stop to make two sentences.
  • Bob loves baseball and he plays every Sunday.
  • Bob loves baseball. He plays every Sunday.
  1. Separate with a semicolon (;) and a transitional word.
  • Hank loves baseball and he plays every Sunday.
  • Hank loves baseball; therefore, he plays every Sunday.
  1. Separate with a comma and “but”, “or”, “yet”, “so”, “for”, “and”, or “nor”.
  • Hank loves baseball and he plays every Sunday.
  • Hank loves baseball, so he plays every day.
  • Hank loves baseball, but he never plays.

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