I'm curious about that. What is it like, working as a programmer or doctor or ___ in a foreign country, where so much of what you do and learn depends on English?
Well, I generally speak Dutch during the day, it's just the programming that I do in English.
It depends on the project. The project I'm working on now is for the Dutch market, so the names of the entities are in Dutch. Still I like to use English as much as I can in my code. It's easier for Dutch programmers to understand English than it is for international programmers (from cheap wage countries like former Yugoslavia or India) to understand Dutch.
Then again, I've worked on a project that was targeted for international use which used Dutch variable and function names.
But I'm basically a child of the internet generation, I grew up without it initially and when I was about 14 we got our first internet capable PC at home. Because of the dominance of the US on the web, I picked it up very easily. And searches in English would yield way more results than searches in Dutch, so I gladly accepted that English would be the main language of this generation.
I still like to use the English Wikipedia over the Dutch one whenever I'm looking up a global or foreign topic.
You have to understand though that Holland is a very western and international oriented country so even our average Joes will be able to speak some English words. We get movies and TV series in English and put Dutch subtitles under them.
Although English is my second language, because of how often I use it (for these forums for instance), it's more like my 1.5th language. Sometimes it's even easier for me to think of an English way of saying things than a Dutch way and I found myself struggling to translate it back to Dutch.