I'm teaching my son to address my Filipino friends with either Tito/Kuya, Tita/Ate and Lola/Lolo. I don't want him to grow up doing what most people living ing USA are used to when addressing people most especially elderly ones. I remember, I was shocked when I heard for the first time my sister in law called my mother in law by her first name. It was so awkward then because it's considered rude in my culture. People from various cultures have a certain ways of addressing / calling others when conversing. In my country, elderly people are addressed with Mr./Mrs./Miss [Last name] or our native references such as 'Manong or Kuya' [older brother], Manang or Ate' [older sister] even you're not related to each other. Don't be suprised to hear from somebody calling your mom as mom too. It's respect for elders and part of good manners. Here in USA, addressing someone only by their first name is common. Most children call their Aunt/Uncle/Teacher and elders by their first name which is a no-no in my culture, totally inappropriate! Here, regardless of job desc/position, everyone in the company addresses each other by first name. You wouldn't know who's the subordinate or the boss because they are all called by their first name. Doctors, church leaders and govt. officials are not usually addressed by their first name solely. I have an eighty year old co-worker then, whom I was very close with and I never called her by first name only. I addressed her with Miss [first name]. Since each culture has its specific ways of addressing or greetings others, by not knowing how, can create an awkward situation for both. So, is it bad manner to address elderly by their first name? Definitely yes, if you belong to my culture. Is it possible to bring it with you and use it here in USA? Yes, I'm glad to say that I was allowed by my mother & father inlaw to call them mom and dad and they got used with it proven by each greeting cards they sent me, with complimentary closing 'Love, Mom and Dad'. For the others, they signed it with their first names only. I am so fortunate too that my hubby's family is close knitted. My nephews and nieces address us with Aunt or Uncle. No one from them calls their Aunts or Uncles by their first name. So, even it's common here to call each other by first name without considering that as rude/bad manner, you can still do what your culture's traditions are.