proper, little, English ladies..
I've always wanted to meet one of those. I think they're a myth, to be honest.
In the UK, pants are what you wear under whatever you choose to call the US meaning of pants.
That's only true in certain parts of the UK. In Yorkshire, pants mean trousers as well as underpants.
Some other stuff, in the UK, when you've finished a meal at a restaurant you would ask for the bill. In the States, you'd ask for the cheque. Which they would inevitably mis-spell (before someone points it out) as check.
Also, filling in forms and applications. We don't check boxes over here, we tick them.