During third grade, children are really flexing their “idea” muscles and learning to express those ideas in more sophisticated ways. Sentences are getting longer and more complex. Kids are learning to use a dictionary to correct their own spelling. Grammar improves; for example, you’ll see appropriate punctuation, contractions, and correct subject-verb agreement. Third graders can write an essay with a simple thesis statement, examples and supporting details, and a thoughtful concluding sentence. They are building skills in the writing process — research, planning, organizing, revising, and editing (with help from teachers and peers).
Alexander 