Here's a trick that works well for my students.
question: Is it that he's not here?
answer: Yes, (you're right) he isn't here.
answer: No, (you're wrong) he is here.
question: "Is it never possible?"
answer: Yes, (you're right) it's never possible.
answer: No, (that's not what I think is true) it could be possible.
question: "You did nothing?"
answer: "Yes, (that's right) I did nothing."
answer: "No, (that's wrong) I did do something."
question: "You didn't do anything?"
answer: "Yes, (that's right) I didn't do anything."
answer: "No, (that's wrong) I did do something."
question: "Is it never possible?"
answer: "(That's) Right, it's never possible."
question: "You did nothing?"
answer: "(That's) Right, I did nothing."
question: "You didn't do anything?"
answer: "(That's) Right, I didn't do anything."
question: "Is it never possible?"
answer: "No, (I don't believe that) it's still possible sometimes."
question: "You did nothing?"
answer: "No (that's not true)! I did something!"
question: "You didn't do anything?"
answer: "No (that's not true)! I did do something!"
All the best,
