A paragraph is a series of related sentences developing a central idea, called the topic. Try to think about paragraphs in terms of thematic unity: a paragraph is a sentence or a group of sentences that supports one central, unified idea. Paragraphs add one idea at a time to your broader argument.A paragraph is a series of related sentences developing a central idea, called the topic. Try to think about paragraphs in terms of thematic unity: a paragraph is a sentence or a group of sentences that