An example of a main idea would be: summer is the best time of year. The main idea is the subject or topic of a piece of writing or a story.
To find the main idea, first read the paragraph or story and ask what the selection is about. While each piece of writing contains multiple details, it also contains one main topic that all of those details relate too. From there, come up with a statement that summarizes those details and that is the main idea.If the paragraph talks about alligators and how they make nests, hatch eggs, and care for their young, the main idea could be alligator reproduction.