In the course of a conversation in (American) English, I often respond to casual observations and statements using a neutral phrase such as "Oh, interesting" "Oh, I see" or "That's cool." I've realized that I have never been able to translate this and I often find myself using variations of 真的吗？是吗？to acknowledge what is being said.
"Hey, I saw Mary at the store yesterday." 诶, 我昨天在超市见了Mary!
"Oh, cool. How was she?" Umm...Uhh...真的吗? 他怎么样？
I'm basically looking for a phrase to respond to mundane things like "I started taking guitar lessons" or "I saw that movie yesterday" because at least for me, the rhythm of the conversation feels awkward without it.
Does just saying 真的吗？是吗? work for this? Because I feel like saying this over and over again makes me look a super skeptical person, disbelieving that somebody could possibly buy eggs at the grocery store or see that guy at the bank. Because I don't feel like 是吗 and 真的 translates feel of English phrase "oh really?" does it? Is there a colloquialism that is just as versatile as the English saying "Oh, that's interesting."
But I would want to translate "cool" as a way of expressing that I have some fleeting interest in the conversation. Somebody has translated the slang word "lame" as “没趣" for me... so does it follow that cool is "有趣"? I've seen 趣 in th 对 + Object + 感兴趣 structure, but can you colloquially describe somebody as 有趣 or an activity as 有趣 as well? And could I say it in this way in the situation above?