A final way to correct a run-on is to make one of the complete sentences a dependent clause by adding a dependent word (a subordinating conjunction or a relative pronoun), such as after, because, before, even though, if, though, unless, or when. Choose the dependent word that best expresses the relationship between the two clauses.

RUN-ONS (corrected)

When the dependent clause starts off the sentence, you need to add a comma after it, as in the first example above. When the dependent clause is after the independent clause, there is no comma, as in the second example.