used to say you do not understand how sth can happen and would like an explanation :
If she spent five years in Paris, how come her French is so bad?
used to say you do not understand how sth can happen and would like an explanation :
If she spent five years in Paris, how come her French is so bad?
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005