If you take someone up on their offer or invitation, you accept it.
Since she’d offered to babysit, I took her up on it.
PHRASAL VERB : V n P P n
If you take someone up on their offer or invitation, you accept it.
Since she’d offered to babysit, I took her up on it.
PHRASAL VERB : V n P P n
Collins COBUILD Advanced Learner's English Dictionary. Английский словарь Коллинз COBUILD для изучающих язык на продвинутом уровне. 2006