In Europe, every airport capable of accepting international flights (usually this is evident from "Customs" being available) will have English (*) speaking
ATC - at least during the hours when Customs is available.
(*) may be poor English but that's life
However, there is no requirement for any
ground personnel to speak English. I remember this at a few places... Bastia/Corsica, Zaragoza... At Zaragoza even the tourist info desk could not speak English; no doubt they are another Spanish wheeze on100k euros/year. Worst-case, it can literally take an hour to even find the office where you pay for the landing, though this is very unusual.
And if an airport is not international then you do need to speak the local language if you want to fly there. At many, they do speak English. but they don't have to.
Also, in general, if an airport has an
instrument approach, you are likely to have English speaking ATC anyway.