Most jokes are designed to end with a humorous climactic word or phrase. Here's an example from Larry Wilde's book "Library of Laughter:"
I can't understand why you failed in business. Too much advertising. You never spent a cent in your life on advertising. That's true, but my competitor did.
Everything in the joke up to the comma after "That's true" is the setup of the joke. "But my competitor did" is the punch line. The punch line gets its name from the delivery technique used. You must punch the line out a little harder and with a slightly different voice than the rest of the joke. Lean into the microphone and say it louder and more clearly than you said the setup lines. If the audience does not hear the punch line, they are not going to laugh.
Just before the punch line you should pause slightly (to emphasize and draw special attention to the line. After you deliver the line, don't utter another sound. Give the audience a chance to laugh. Words or phrases appended to the climax tend to delay or impede laughter. Until you get some experience, it is really tough to wait. Beginners tend to be afraid that no laughter will come, so they keep going. If you keep talking during this period, you will easily squelch the laughter. As your confidence builds, pausing will become easier and easier. Sometimes waiting the audience out will actually give them a cue to laugh even if the joke wasn't that great.
When you deliver your punch line, deliver it to one person and one person only. It doesn't matter how large the crowd is, you can look one person right in the eye and deliver your line.
Next issue we will learn how to pick the person to whom you deliver your punch line.