语言的阶级问题
ER的私人秘书叫她Ma'am。又来引Wikipedia:
In English-speaking countries, the wife of a foreign dignitary is called Madame (note final 'e') in direct address and formal correspondence, rather than the equivalent word in the person's native language (Señora, Frau etc.).
After addressing her as "Your Majesty," it is proper to address The Queen of the United Kingdom as "Ma'am" for the remainder of the conversation.