‘A while’ is not something I say, but I’ve noticed that many people do.  I’ve also noticed that ‘a while’ has an infinite number of meanings.

I’m not very good at reading minds and when I guess how long your ‘a while’ is my strike rate at guessing right is pretty low.  So… I ask.   When I’m told something is going to take ‘a while’ my very next question is “so how long is a while?” 

‘A while’- sometimes it means a minute, sometimes it means a month.  Asking works for me.