I have a friend who've half British, half Swedish, and grew up in the UK. As her dad really struggled to learn Swedish (ie didn't try very hard!) her parents decided to bring their children up speaking only English, so as not to "split the family". This has been one of the biggest regrets in my friend's life - she really loves the Swedish culture (which is 50% of her after all) but can't fully appreciate it because of the language barrier. She can't really communicate with half her family and grandparents. Although she's made the effort as an adult to learn Swedish, she will never be fluent enough to live and work there, where English is hardly spoken. Quite selfish on the part of her father i always thought - i'm sure in time he'd have learnt enough so as not to "split the family".