The naturalization test also checks that you can read and write in English. Take a Writing Test or Reading Test in the real USCIS format (1 of 3 sentences correct passes), or practice with 16 reading and 30 writing sentences built entirely from the official USCIS vocabulary.
Like the real interview: you will hear up to 3 sentences, one at a time, and write each one. Get 1 right and you pass. Small spelling, capital letter, and punctuation mistakes are okay. Do not abbreviate words.