Writing

Run-on sentences are independent clauses that have not been joined correctly. An independent clause is a word group that can stand alone as a sentence. It has a subject, a verb, and it makes sense by itself.  Clause  = S + V

If you have two independent clauses in the same sentence, you must join them, or you must separate them completely. 

• Join with a comma and a coordinating conjunction (the FAN BOYS - for, and, nor, but, or, yet, so)
• Separate with a semicolon (or occasionally with a colon or dash in informal writing)
• Separate into two sentences with a period

The following is a run-on sentence. One independent clause is underlined, while the second is in bold.

The clock tower has been broken for six months it makes me late to class every day.

These are two separate clauses (S + V) that need to be joined or separated. Here are a few ways to do this:

•  Join with a comma and a coordinating conjunction:

                           The clock tower has been broken for six months, so it makes me late to class every day.    

                           The clock tower has been broken for six months, and it makes me late to class every day.

• Separate with a semicolon:

                           The clock tower has been broken for six months; it makes me late to class every day.

• Separate into two sentences with a period:

                           The clock tower has been broken for six months. It makes me late to class every day.

Finding Run-ons

If you are not sure a sentence is a run-on, try using the question method. Separate each clause into a yes/ no question, and if it makes sense as two separate questions, then it is a run-on sentence.

Example:  The clock tower has been broken for six months it makes me late to class every day.

Has the clock tower been broken for six months? YES

Does it make me late to class every day? YES

Since both of the above independent clauses make sense as a question, it is a run-on sentence, and you need to fix it.