to know when you should do sth in order to be polite :
You think he'd at least have the courtesy to call to say he'd be late.
to know when you should do sth in order to be polite :
You think he'd at least have the courtesy to call to say he'd be late.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005