As of 2015, U.S. Citizenship and Immigration Services hosts four free online naturalization practice tests on its official website to help candidates prepare for the civics test. These tests assess knowledge of U.S. history and government.
An individual seeking naturalization is asked up to 10 questions from a pool of 100 U.S. civics questions during his naturalization interview, explains USCIS. The applicant must correctly answer at least six of these questions to pass. All of the questions are available in text and MP3 audio format in both English and Spanish on the official USCIS website. Flashcards, videos and study booklets are also available.