A picture or a story is about something.It has a subject .Read this story and think of what the story is mainly about.Sue was tired of the rain.It had rained all day.It rained yesterday,too.The first sentence tells what the whole story is mainly about.A sentence thetells what the whole story is mainly about the main idea.The last two sentences tell why sue was tired of the rain.They are details. Sometimes a sentence in the story tells the main idea.Sometimes there is no main idea sentence.Then you have to ask yourself,“What is the story about?” Read this story and think of what it is mainly about. Jeff brushes his dog′s fur.He give his dog fresh food and water.He takes it for long walks. This story tells just details.You can guess that the main idea is “Jeff takes good care of his dog.”because all the details tell about this main idea.