Run-on Sentences

The term run-on sentence is used to describe two or more independent clauses put together without punctuation between them. This is a very common error among new writers in English.

The Petronas Towers are enormous steel buildings in Kuala Lumpur they are the tallest buildings in the world and they were built on a racetrack.
The Empire State Building is 1,252 feet tall was built in 1931 it was built in New York.

These two sentences are run-on sentences; they both go on after the simple sentence is finished.
We can fix these run ons by simply dividing the run-on sentences into two sentences.

The Petronas Towers are enormous steel buildings in Kuala Lumpur. The are the tallest buildings in the world and they were built on a racetrack.
The Empire State Building is 1,252 feet tall. It was built in 1931 in New York.

If you have two independent clauses--complete sentences--without periods or a conjunction joining them together, they are run-on sentences and need to be fixed.

Here's another run-on sentence.

The World Trade Center towers were completed in 1973 they were the tallest buildings in the world for only one year.

Since these two independent clauses are closely related, they can be combined into one sentence if you use a semicolon. The semicolon is the only punctuation (other than a period) that is strong enough to hold together two independent clauses:

The World Trade Center towers were completed in 1973; they were the tallest buildings in the world for only one year.

Finally, two independent clauses can be combined into a compound sentence, using a conjunction such as and, or, nor, but, yet, so, or for.

The Petronas Towers are 1,483 feet tall they each have 88 stories.
The Empire State Building is not as tall as the Petronas Towers it has 102 floors.

These sentences can be fixed by using a conjunction plus a comma to tie them together:

The Petronas Towers are both 1,483 feet tall, and they each have 88 stories.
The Empire State Building is not as tall as the Petronas Towers, yet it has 102 floors!

Fixing run-on sentences makes your writing more elegant and easier for your readers to understand.

Practice #1