Originally Posted by
rcspeirs
We could happily be here for weeks with the differences in language.
Not quite the question you asked, but to avoid major confusion when traveling about, do not abbreviate the names of places or streets. That's a recipe for confusion and possibly inadvertent misdirection.
Indeed, asking how to get to Oxford is very different to asking how to get to Oxford Street.
Broadly agree with the other responses above, although I would say do use the term Underground or Tube rather than Subway.
Probably the most common difference heard from foreigners is asking for the bathroom rather than the toilet or loo, but that is so common it won't generally cause any confusion, and in fact (shock horror) some British English speakers have migrated to using the bathroom term in restaurants etc.