Highly depends on the country. Go to Sweden and you'll have a hard time even practicing Swedish, as soon as the natives discover you're also not a native, they'll switch to English immediately in most places of the country.

On the other hand, go to Spain outside the metropolitan areas and besides the youth, most people won't understand and can't speak English.

Then you have places like France, where even if many of them know English, they'll just refuse to speak English, unless it's an emergency, then English comes out of them with no problem. Then some French tourists also like to travel down to the North of Spain and try to talk French with us, for some reason. I cannot even count these occurrences on one hand anymore.

It really depends on the country and maybe more importantly, rural vs metropolitan areas.

Besides, humans are surprisingly good at communicating just with our hands, faces and pointing at stuff, you can definitively get by as a tourist in a country without sharing any spoken languages, and after a few days you'll both learn some of the basic words of their language, and "shortcuts" for pointing/hand-waving through what you want, making the whole thing a lot easier :)

Also relevant to note that some European countries dub everything while others sub. That no doubt plays a part in the population’s understanding of foreign languages.

> and "shortcuts" for pointing/hand-waving through what you want

To expand on this idea, there are books designed specifically for travels which are pocket sized and contain a bunch of images so you can point at what you want.