Student or Learner
Suppose you were asked to do something together, but for what ever the reason, you had to say "no" . And so you'd like to apologize for not being sociable.
What kind of lines are usually used in this kind of situation?
Also lines like these are usable?
"Sorry for being a party pooper."
"Sorry for not being sociable."
Please teach me your usual lines or commonly used expressions.
Those two are fine. 'Sorry ...' or 'I'm afraid ...' (or the now rather old-fashioned 'I fear...') can be followed by pretty much anything.
A formal refusal is in the 3rd person: hence the song title 'Miss Otis regrets'.