Several of them (or their siblings) went to international schools; and depending on the country, they might encounter English a lot in daily life. Especially countries were tv isn't dubbed but only subtitled, the exposure is quite extensive for most children and especially teenagers.
International schooling of heirs and their siblings as part of secondary education:
- Belgium: Elisabeth went to United World College in Wales; while her siblings went to the International School of Brussels (before that they went to a Dutch-language school as they speak French at home)
- Denmark: all siblings went shortly to an international school in Verbier, Switzerland before they had to return home earlier than expected.
- Luxembourg: Guillaume and brothers went -among others- to an international boarding school in Switzerland (Collège Alpin International Beau Soleil)
- Netherlands: Alexia and Ariane both went to (different) United World College
- Norway: Ingrid-Alexandra and Sverre Magnus went to the International School of Oslo
- Spain: Leonor and Sofia successively went to United World College in Wales (before that they attended month-long summer camps in the States)