All of the staff spoke English -- all officers seemed to be fluent. Much of the crew was from the Philippines and did fine with English. Communication with staff was easy in English. Tours were in English unless you booked one in another language. During the shows, they made announcements in many languages, but English was always one of them. Blue Man Group has some video elements that all are in English. I believe that most of the entertainment, like the dueling pianos and the game shows, are all in English unless specifically noted otherwise. All kids club staff that we encountered seemed to have English as their primary language, or at least were close to fluent in it.
The other cruisers, though, were definitely mixed. I would say that the majority of the cruise was comprised of Europeans. Maybe 20 percent from the USA or so? So, there were definitely language issues with other guests. And, to be sure, cultural ones. For example, it seems that the further east you go, the less of a custom it is to let others off the elevators before you try to enter. I found this to be fascinating. There's a really good reason why one would unload first before loading -- not just to be polite, but because it actually doesn't work well the other way. But, by and large, there were many whose languages made them sound like they were from eastern parts of Europe who were definitely used to a different custom. This is just one silly example, but there were many -- different views of how to board a bus, lines at buffets, etc. After some initial annoyance, once you realize that it's not rude if it's your custom, it was kind of interesting -- the whole reason to you visit other parts of the world. I'm sure most European cruises are the same, although my hunch (with no basis other than that Disney is heavily associated with the USA) is that
DCL European cruises have more Americans than some of the other lines.
But, in the end, English was the official language of the ship and dollars were the official currency.
