1.
back-channel response, verbal nod
Short verbal responses such as うん, ええ, そうですね given by a listener during conversation to show they are paying attention. A fundamental part of Japanese communication.
相槌を打つ。
To give back-channel responses.
話を聞きながら相槌を打った。
I gave verbal nods while listening to the story.
日本語の会話では、適度に相槌を打つことが大切だ。
In Japanese conversation, it is important to give back-channel responses at appropriate intervals.
KEY PATTERN:
相槌を打つ is the standard collocation meaning "to give back-channel responses."
ETYMOLOGY:
From blacksmithing: 相 (mutual) + 槌 (hammer). Originally referred to the assistant smith striking the metal in rhythm with the master smith, hence the idea of responding in sync with the speaker.
CULTURAL NOTE:
Back-channeling is far more frequent and important in Japanese conversation than in English. Failure to give 相槌 can make the speaker feel ignored. Common responses include うん, ええ, そうですか, なるほど, and へえ.