There are a lot of places in the US that sell ``pints'' of beer in ``cheaters'', which are glasses that appear to be 20oz glasses, but which have over-thick walls and bottoms, so that they contain well less than 20oz. Are you sure that you got 20oz?

When we asked the waitress for "three more Sam Adams", she said, "Uh, this one's an Imperial" and it was only then we noticed it looked like a bigger glass (pubs in the UK often have several different shapes of pint glass, and it's pretty random which one you get).

Is it fairly common to serve 20oz pints in the US, then? Do people actually ask for "an Imperial Sam Adams" if that's what they want, or do some places serve 20oz pints by default?

Of course, that wouldn't explain why you got a differently sized glass than your colleagues. Was your beer on tap and theirs from bottles or something?

Dunno, perhaps it's in what they asked for ("two Sam Adams"). Maybe they even got a different bartender (they turned up a few minutes after me), one who didn't have the "English accent, serve Imperial measures" heuristic.

Peter