Re: “Please accept my apology / apologies”
:up: But if you do use the singular there can be the implication that you're referring to a particular sorry-saying event: 'I told him I was sorry and assured him that it won't happen again. He seemed to accept my apology at the time - but we'll see.'
This sort of 'dummy plural' (not an official term, as far as I know ;-)) tends to happen with social exchanges of various kinds. At the end of a party you 'say your goodbyes'. You might think that a plural makes sense there, because you say goodbye separately to a number of people. But children at b8rthday parties are often told to 'say their thank-yous' - referring to only one thank-you, to the host/hostess. When you 'make your excuses and leave', there's usually only one excuse: 'Well, early morning for me. I can't go on to the club.'
So I think, in most cases that involve apologies, I'd use the plural unless I wanted to be specific about its one-ness.
b