A: Absolutely not! I work with a lot of internationally living parents, and this is a common misconception; that it would be more valuable for them to use English with their children, to make sure they have English as a “mother tongue”. I’ve even met families who want me to help them change their child’s mother tongue. This is of course not possible, you can change a child’s dominant language, but you can’t change their mother tongue. At the root of the question of prioritising English over a home language is the belief that English is the language their children need most to “get ahead”. It is true that for most internationally living families, English is important. It is also true, however, that English is the language that needs little help in becoming important. We have a very small window, when our children are young, to pass on as much of our minority languages as we can. From the moment our children start in English-language school (or pre-school), English begins its journey to take over. I chose the photo above for the little Pac-man like creature in the corner – I tell parents all the time that English is a Pac-man language; it comes in and starts gobbling up all the other languages that children know, until they are left with only English. That may sound dramatic, but most parents of English-schooled children will find this to be true, and the minority languages become increasingly more difficult to maintain and develop.
So if you are raising a child who will eventually need English, don’t let that interfere with your job of passing on the family languages to your children. Those languages are connected to who they are and where they come from, and will be a critical part of their identity. The early years, before English becomes omnipresent, are the time to develop the family languages as much as you can. Trust that the English will come, and that you don’t need to start any earlier than necessary.
on raising bilingual children 
I always ask parents to think ahead to their grand-children, and how they would feel if they couldn’t communicate with their grandchildren in their own language in a generations time… with this type of conversation emotion is the thing that counts, emotion and identity.
If they don’t care, that’s a choice, but many stop in their tracks thinking about that, that their language could die out in their family in their time, and then I ask them to extrapolate over all families in their situation…
Yes, I agree. Parents sometimes are thinking about what they feel is best for their children right now, but they disregards, the door they are closing by choosing not to use a family language. At the very least, they should put a lot of thought into that decision.