This exercise practices changing singular present tense forms from affirmative to negative and vice versa. If the form is affirmative, change it to the negative form of the same person (1st, 2nd, or 3rd person). If the form is negative, change it to the affirmative form of the same person. When you have finished, you can check your answers and try again. The "Get new questions" button will randomly select another group of questions.