うんうん

うんうん
interjection
uh-huh, yeah yeah
informalspokencommunication
1. uh-huh, yeah yeah, mm-hmm
A casual back-channel response indicating that the listener is following along and encourages the speaker to continue. Repeating うん emphasizes active listening.
昨日(きのう)」「うんうん」「映画(えいが)()」「うんうん」
"Yesterday, right?" "Uh-huh." "I saw a movie." "Uh-huh."
"And then, I ran into them at the station." "Uh-huh, and then?"
While listening on the phone, I said "Uh-huh, got it."

うんうん is the reduplicated form of うん (yeah). The repetition signals active, engaged listening — the equivalent of the English "uh-huh" or "mm-hmm" back-channel.

BACK-CHANNELING (相槌(あいづち)):
Japanese conversation relies heavily on back-channel responses (相槌(あいづち)) to show the listener is engaged. うんうん is one of the most common. Others include:

  • うん: simple acknowledgment
  • うんうん: active listening
  • へー: mild surprise or interest
  • そうなんだ: "is that so?"
  • なるほど: "I see"

Register

The rhythm and intonation of うんうん convey engagement. A flat, mechanical うんうん may suggest the listener is not really paying attention, while a lively, varied うんうん shows genuine interest.
うんうん is casual. In polite settings, ええ or はい is used instead. Using うんうん with superiors or in formal situations is too familiar.