Everyone knows how to play tic-tac-toe, and there is virtually no end to the ways it can be used in the ESL classroom. Just fill in the spaces with the day's target language, divide the class into two teams, and you're off. Have the students make correct sentences, match new vocabulary to pictures, or produce antonyms. Teams get X's and O's for correct answers. To up the stakes, take X's and O's away for incorrect answers.