How to avoid run-on sentences?

A run-on sentence is a common error found in the writings of ESL students. It is easy to avoid run-on sentences. You just need to make sure that clauses are either connected by a conjunction or separated by a full stop or a semicolon.

Read the two clauses given below.

• I am on a diet.
• I want to lose weight.

You can connect these two clauses using a subordinating conjunction.

• I am on a diet because I want to lose weight.

Now consider removing that conjunction because.

• I am on a diet I want to lose weight.

The sentence given above is a run-on sentence because there is no connection between the two clauses.

More examples of run-on sentences are given below.

• Copernicus was a great scientist, he knew that the sun was the centre of the universe.

Here the two clauses are separated by a comma instead of a semi-colon, a full stop or a joining word.

It could be rewritten in several different ways.

• Copernicus was a great scientist; he knew that the sun was the centre of the universe.

Here we use a semi-colon to separate the two clauses. Semi-colons are sometimes used instead of full stops, in cases where sentences are grammatically independent but the meaning is still closely connected.

• Copernicus was a great scientist. He knew that the sun was the centre of the universe.

Here we use a full stop to separate the two clauses. This arrangement is perfectly fine, but if you separate all clauses with a full stop, your writing will be full of simple sentences. It could lower your score because an overdose of simple sentences in a piece of writing is clearly an indication of poor writing skills.

Ideally you should connect your clauses with a conjunction or a relative pronoun. Of course, sometimes this is not possible. In that case, don’t hesitate to separate them with an appropriate punctuation mark.

Let’s go back to our example sentences. Read the sentence given below.

• Copernicus was a great scientist in that he knew that the sun was the centre of the universe.

Here the two clauses are connected using the subordinating conjunction in that.

Another example of a run-on sentence is given below.

• The camel doesn’t have great looks it has a huge hump on its back.

We can correct this sentence in many ways.

• The camel doesn’t have great looks; it has a huge hump on its back.
• The camel doesn’t have great looks because it has a huge hump on its back.
• The camel doesn’t have great looks. It has a huge hump on its back.