There are two ways to use repetition to make something funny:
You can repeat what was said earlier, but in a different context that makes it funny.
Or you can either repeat the punchline of a joke said earlier.
Examples of repeating what was said earlier in a different context would be:
If a friend mentions how some puppies can chew through anything, then later you are struggling to open a jar of peanut butter, as a joke you can say “This jar is hard to open. We need a puppy.”
In a dinner with friends, someone talks about how a famous actor turned up late for an interview because he was busy playing basketball. Later during dinner, one of your friends hasn’t arrived yet and will be late. As a joke, you can say, “He is busy playing basketball.”
If done correctly, and with the right groups of people, this will create laughter. Just make sure not to repeat it too many times.
Examples of repeating the punchline of a joke said earlier:
At a gathering at a friend’s house, someone accidentally places a sandwich into the microwave for too long and it comes out overcooked, and someone as a joke says, “It looks like the microwave did not like that sandwich.” Later at that same gathering people are talking to Michael who has been applying for jobs but not having any success, and someone ask him how is the job hunting going. As a joke he can say “It’s hard, nobody will hire me. They hate my resume more than the microwave hated that sandwich.”
If a friend is asks to bring food to a dinner gathering, but after asking everyone he forgot to, then when people ask him what happened, as a joke he says, “I was robbed by an invisible burglar.” If later during dinner, you have misplaced a spoon or fork, and people ask you what happened to it, as a joke you can say “That invisible burglar came back and stole it”.
This is also how what is sometimes referred to as ‘inside jokes’ are created. ‘Inside jokes’ are basically jokes that only a few people get because they understand the history behind it. Back when I was studying at university in my very first week, me and a friend of mine met a student in our lecture. He sat next to us, and we thought we had made a friend. Ten minutes into the lecture, he told he got a phone call and will be back, and left the lecture. He never came back.
We made jokes about how we thought we had made a friend, but then he left because that was how boring he must have thought we were. We found it hilarious, and told a few other friends we had about it. For the rest of the semester, it became a running joke among our friendship group. If someone couldn’t make it to something we organised such a study group, before explaining why, he or she would just say “I had a phone call”. We would all crack up laughing, both because of the absurdity of the excuse, and also because of repetition.
Someone who did not know the history behind that, would not understand why it was so funny. But those who did, would find it funny. It was an ‘inside joke’.
The purpose of an ‘inside joke’ is not to make those who do not know it feel excluded. And you should not be aiming to create jokes that only a few people will understand. I only explained ‘inside jokes’ so you would understand how it is created and the potential that using repetition has.
It also helped that I had a group of friends who had a great sense of humor and loved laughing about these things. We also did not keep repeating it to the point where it became boring or annoying. Remember too much repetition can be bad. And repeating the wrong thing that was said is also bad and can be hurtful to others. So don’t repeat something inappropriate someone said that should be forgotten.
A note of caution with making jokes. You should only make jokes with people who will not take it seriously or take it the wrong way. There are some people and situations where making jokes is a bad idea. There are some topics which you should not make jokes about. As with all other social matters, use common sense. If you are not sure whether what you say might be offensive, or if the person you are talking to will not appreciate jokes, then don’t make any jokes.