[gield]

I respectfully disagree, based on anecdotes. The Dutch-speaking part of Belgium subtitles everything, except for shows meant for kids <8 years old. The French-speaking part on the other hand dubs everything, even interviews in the news. Guess which part of country sucks at speaking English.

[hrasyid]

My point is you need to watch the target language audio with no subtitle in your language.

If the choice is English-audio + Dutch-subtitle vs French-audio only, then of course there is no advantage to the second group. Try restricting the French-speaking kids to watch shows with English audio only.