It's not easy. Not knowing your situation, I can only assume this is someone you're interested in, and/or might be involved with. In any event, as a guy who's been labeled "shy", "passive", "non-social", "introverted", "not talkative", etc..., it's bothered me because I don't consider myself any of those. It's just when in certain situations, I may feel uncomfortable talking. For example: around a large group of people, strangers, me talking when 4 or more people are watching/listening to me, or when I see an attractive girl I would love to talk to, but I don't have the courage, or if someone introduces me to an attractive girl I freeze up at times. I'm getting much better; HOWEVER. No matter how quiet someone is, or no matter how shy they are, they have a story to tell. Just like the posts here, ask questions. Find out what they are passionate about, and they will talk about it. Anytime I get uncomfortable talking, I always try to turn the spotlight on someone else by asking questions. I'm not avoiding the situation, but when I do that, I try to create this dialogue, and I end up talking more when I find a common interest with the person(s) I'm talking with. Plus, if you can say something to create any kind of laughter, that's a bonus, because it's an ice breaker and it reduces a lot of anxiety of not wanting to talk. I assure you if you find out what they're passionate about, they will talk about it and hopefully they will open up a bit more. Good luck, keep us posted!
TGun