With “not” you can really say what you truly want and “not” let the other person really know. “You worked really hard today……not”. “I think that you paid the right price for your hairstyle….not”. See how easy it is, to be honest as long as you delay your honesty with the last word. This 3 letter word can make all the difference in the world especially when you want to say a 4 letter word instead.