If you require some information you can say:Could you tell me if/when/how much/why...?I wonder if you could tell me...?I'd like to know...I'd like some information about...If someone asks you for information you can reply:As far as i know...Well,(in confidence,) i can tell you that...I'm afraid i don't know...I've no idea,I'm afraid...I don't have that information available just now,can i call you back?I'm not sure,I'll have to find out,Can i let you know tomorrow?I'm afraid i can't tell you that,it's confidentail.