[lambdaphage]

Girlfriend's family is from Flanders, the Dutch-speaking region of Belgium. Her sister speaks fluent English despite very modest formal language training. (On the order of the n<=3 years of Spanish or French that most American students take without much to show for it.) She did, however, watch a lot of subtitled TV.

There are about 20 million Dutch speakers, vs. perhaps 400 million English speakers in the US and UK, which have large markets for TV shows and movies with correspondingly large budgets. For the average Dutch speaker, the subtitled offerings in English are apparently much richer than the home-grown stuff.

This, at least, was how it was explained to me by multiple independent Dutch-speaking Belgians who all had an embarrassingly firm command of idiomatic English.