Pardon me

As I've lived in the UK for quite some time now, I'm pretty thoroughly fluent in Ameringlish. That doesn't mean that I am a convert and use the British word. I've transitioned on some, but there are many language changes that I can't bring myself to make.

I call is a diaper and not a nappy 99.9% of the time.
I still say ZEE-bra and not ZEB-ra (which starts with a letter ZEE not a ZED).
I say garbage can, rather than rubbish bin most of the time.
I will always say "y'all".
I ride the elevator not the lift.
Sometimes I queue, but usually I get in line.

Consequently, I worry that Linus will end up confused about how things should be said and what things are called. As he gets older and starts school, I know that he'll be inundated with the British way of saying things and will probably defect. (Except for using y'all. I'll insist on that.) I'm mostly ok with using different words and figure that Linus will work it out for himself. He's a smart kid. He doesn't get confused when Ross and I say things differently. After all, they say it's good for kids to learn different languages at a young age. That surely applied to two versions of the same language, right?

There is one area, so far, that I've consciously made the effort to switch to a British way of saying something. It is only in making the switch that I've realized how very often I used to say "huh?" or "what?" or even "excuse me?".  In England, the accepted polite way of asking for clarification or repetition of something you haven't quite heard is "Pardon?"

Initially this felt and sounded super-awkward to my ears. All I could think about was this old commercial.

I decided to make the switch because, though I don't object to Linus being considered weird for using a different word- I do object to him being viewed as rude. So that's where I've drawn my personal line in the verbal sand.

If I can use the word that feels most authentic and natural to me, I will. If it's a question of manners or being offensive, I'll make the change.

How do you decide what words to adopt?