Aizuchi

Aizuchi (Japanese: 相槌 or あいづち, IPA: [aizu͍t͡ɕi]) is the Japanese term for frequent interjections during a conversation that indicate the listener is paying attention and understanding the speaker.
 Aizuchi are frequently misinterpreted by non-native speakers as agreement on the part of the listener, because common aizuchi include:

• "hai", "ee", or "un" (yes, with varying degrees of formality)
• "sō desu ne" (I see.)
• "sō desu ka" (is that so?)

  Business relations in particular can be hampered by non-native speakers assuming that their Japanese counterparts have been agreeing to their suggestions all along, when in reality the Japanese have only been saying that they understand the suggestions – "got it", not "agreed".