Welsh and Hawaiian were saved from extinction. Other languages might not be so lucky

Hong Kong (CNN)At work in central Hong Kong, David Hand is surrounded by people speaking Chinese and English. But inside his home, the Welsh language rules.

Hand's three children -- Arwen, Huw and Tomos -- have never lived in Wales, spending their entire lives in Asia.
Inculcating his native language in them thousands of kilometers from the only place it is widely spoken wasn't easy. As well as only speaking to them in Welsh himself, Hand hired nannies from Wales -- usually teenagers taking time out between high school and university -- and arranged for them live to with the family.
    Their Australian mother speaks to them in English.
      "As the kids were growing up until