This is perhaps one of the most common errors in blog writing. Run-on sentences might be something that writers have heard of before, yet they continue to make this mistake. A run-on sentence refers to a sentence that connects two independent clauses together inappropriately. What exactly is an independent clause? Quite simply, it refers to a complete subject and a complete verb that can stand on its own as a sentence. So, in plain terms, you can refer to an independent clause as a sentence on its own. To avoid this mistake, do not connect two independent sentences together unless you can use a comma or a semi colon, or even a conjunction (for, but, and, or, so).