A poco

What is the perfect response to mildly surprising news that you may or may not care about? Imagine that someone tells you that their cousin is finally getting married. You don't really care, but to be polite you respond: A poco. Interesting.

• A poco. Oh.
• ¡A poco! No kidding! That's unbelievable. Are you serious? Wow. You don't say!
• A poco se fue a Estados Unidos. So he went the US? Oh. I didn't know that.
• A poco lo conoces. So you know him? That's news to me. O sea, ¿lo conoces? Órale.

Sometimes a poco includes the idea of disappointment or baiting and mockery:

• A poco te quieres quedar. I'm surprised to learn that you want to stay at this boring party.
• A poco tienes miedo. So you're afraid? I'm surprised to see that. Wuss!
• A poco vas a dejar que te gane. You're going to let him beat you? I expected more from you.

¿A poco no?

¿A poco no? can express surprise about something not being true. It works especially well for expressing skepticism.

• ¿A poco no conoces la marca? Are you honestly not familiar with this brand? I'm a little surprised you aren't. I might believe you or I might not.
• A poco nunca has subido nunca al metro? Are you saying you've never taken the metro? That's hard to believe. Or maybe I believe you and I'm just expressing surprise. Your intonation and the context will determine which interpretation is understood. Note that this one has nunca instead of no.
• Pero te gusta, ¿a poco no? But you like him, don't you? I think you like him, but I see that you don't want me to know. Pero te gusta, acéptalo. But you like him. Admit it.
• ¿A poco no te sientes mejor? Now don't you feel better? I can see that you feel better but I want you to admit it. You feel better now, don't you? Isn't that right?

I've written these with question marks but a yes/no response is not expected. Intonation is falling, just as with English tag questions such as Isn't that right? and Aren't you?