Asking a follow-up question is the easiest proof you were actually listening.

Listening is invisible until a second question proves it. Anybody can nod; a follow-up shows you held what they said and wanted more of it, which is why one small question does more for a conversation than any amount of agreeing. It also makes people feel known rather than merely tolerated, and it costs nothing but attention.

Try it once a day for a week. When somebody tells you something, ask one specific thing about it instead of replying with your own version. Then wait through the pause before filling it.