Rhetorical devices are ways of using language that can help an author advance his or her perspective. Here are three of the many rhetorical devices that writers sometimes use to promote their viewpoint.

Analogy—a comparison to something familiar to make an idea clear
The singer’s voice was like nails on a chalkboard.

Hyperbole—the exaggeration of a statement or a truth for emphasis
We need to improve the coast road because everyone in the state uses it to access the beach. 

Juxtaposition of contrasting ideas—the side-by-side placement of similarly constructed ideas in order to draw attention to their differences (sometimes called antithesis)
“To err is human; to forgive, divine.” –Alexander Pope