Complex sentence: Rhetorical modes (also known as "modes of discourse") describe the variety, the conventions, and the purposes of the major kinds of writing; four of the most common rhetorical modes and their purpose are exposition, argumentation, description, and narration.
Split into simpler sentences: Rhetorical modes (also known as "modes of discourse") describe the variety, the conventions, and the purposes of the major kinds of writing. Four of the most common rhetorical modes and their purpose are exposition, argumentation, description, and narration.