I'm an American visiting Prague and don't speak any Czech, but that wasn't a problem at all. The…read morestaff at Bowling Smíchov greeted me warmly and did their best with English -- it was more than enough to make me feel welcome. The place is clean, spacious, and has a great atmosphere. There are dart boards, plenty of lanes, and lots of room for a big crowd.
It was a little busy when I arrived, but they still managed to squeeze me into a lane solo, which I really appreciated. I spent a few hours bowling, enjoying some great Czech beer (which was absolutely perfect), and just relaxing.
If you're looking for a fun, friendly place to unwind with a few games and a couple of beers, I highly recommend Bowling Smíchov.