Introduction to Topic Sentences and Supporting Details


Writers back up their points with evidence, examples, illustrations, specific instances, and other kinds of information to clarify or explain their point of view. Readers come to understand and, sometimes, to be convinced of writers’ main ideas through their use of these supporting details.

Supporting details usually form the bulk of a piece of writing. Readers expect proof, and good writers provide it. A well-told story can help a writer make an argument without being repetitive. A complex idea can be clarified with an illustration such as a chart or graph. Examples and specific instances add interest and evidence to a statement of fact.


This video illustrates how supporting details contribute to the main idea. Finding the main idea often means figuring out what larger group of ideas an example belongs to. This video demonstrates the concept by showing silhouettes to convey the large group and full-color versions to showcase the specific example. The relationship between a main idea and supporting details is further explained using an outline.

Download transcript.


The study pages include practice activities with short passages. As read you through the study pages and practice with LearningCurve before taking the post-test, try to visualize the relationship between main idea and supporting details either by thinking of illustrations or by making an outline.

Don’t forget to work smartly!