Grammatical joke: But sometimes a double negative is still a negative. However, a double positive never forms a negative Pupil from the back of the room: #8

Teacher: "A double negative usually forms a positive. But sometimes a double negative is still a negative. However, a double positive never forms a negative." —Pupil from the back of the room: "Yeah, right."
Teacher: "A double negative usually forms a positive. But sometimes a double negative is still a negative. However, a double positive never forms a negative." Pupil from the back of the room: "Yeah, right."
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