We'll have to leave fairly promptly (= on time) if we want to catch that train.
如果我们要赶那趟火车,就得准时出发。
We try to answer readers' letters as promptly (= quickly) as we can.
我们努力尽快答复读者来信。
She promised she'd keep it secret and promptly (= immediately after) went and told Dad!
她答应了要保密,随后却立马去告诉了爸爸!