Use a semicolon to join two independent clauses with a transition word or phrase, such as for example. A comma must follow the transition phrase.

Beth hadn´t studied; therefore, she failed her exam.

Explanation:

An independent clause is a group of words that can stand alone as a complete sentence. Transition words can be used to connect two independent clauses with a semicolon. In this structure, the semicolon is used instead of a period, and a comma should be used to separate the transition word from the rest of the sentence.

The sentence structure would be as follows:

Independent clause + semicolon + transition word + comma + independent clause.