well if they born in UK definitely they will learn english.. my husband is British and there's no way he will speak our kids tagalog.
through my readings kids age from 2 to 5 years old, can easily learn different languages and it's the best time to teach them. Kids learn foreign languages more easily than adults do.
their nationality will be British but their blood is half English and half Filipino. i've been a private tutor for Koreans and Chinese kids, so far i haven't got any students who struggle at school. for they learned quickly English and Tagalog. also maybe it depends on the capacity of a child to learn.. they will only fall behind other kids in their class if they are not bright enough.![]()