我刚去查了下，发现挺有意思的。
Mum/mummy is British, mom/mommy is American.
但是有人留言说New England in America也是用mummy。
然后有个英国网站上发现了有趣的留言：
有个妈妈说：I would never use Mommy, very American. My daughter went through a phase of calling me Mammy, think she sensed her Northern roots!
