Normally, anywhere between 2-6 single measures (so 50-150ml), depending on what mood I'm in and if I'm working the day after or not. I certainly don't drink it every night though.
And as for developing a taste for it?
Well, I started off by occasionally drinking the odd blend with ice in it as a last drink of the night on a night out (this started maybe 2-3 years ago). Then I tasted a Scottish single malt for the first time sometime last year, and subsequently bought a bottle of it. Then I bought a second, different bottle... and another... and another... up until now, where I have 34 different Scottish single malts, a blend (Black Bottle, for those interested) and three small bottles of Irish whiskey. All of which are open. I also have a small reserve stock of a few of my favourite bottles. So all in all I have around 42 bottles of whisky/whiskey in my room.
So yes, I'd say you can develop a taste for it
I suppose the scariest part of all this is my age: I'm 23 (let me reiterate that I
don't drink the stuff every night!). Which leads me to asking a question: how old is everyone here that drinks whisky on a regular/semi-regular basis?