On Monday, I talked about the word うん for “yes” which is very often used in casual conversations.
To confuse western ears, Japanese children (and adults) often say ううん for “no” although I don’t recommend grown-up readers here use it (but you should be able to tell “Yes” or “No” when your friends are talking to each other)..
Listen to the audio to hear the difference!

うん (Yes)

うん、すき。(Yes, I like it)

ううん (No)

ううん、きらい (No, I don’t like it.)