When I was a kid, I would collect rainchecks from people who were leaving the stadium.

当我还小的时候，我会从离开体育场的人们那里收集票根。

'I can't tonight, but can I have a raincheck? '

“我今晚去不了，但你能改天再约我吗？”

And we also use raincheck to refuse an invitation, but say we might accept it later.

我们也可以用 raincheck 来拒绝邀请，但会说我们可能以后再接受。

And at the end of the summer, we would trade them to see who could collect the most complete set of rainchecks.

在夏天结束的时候，我们会交换它们，看谁能收集到最完整的一套票根。

The rain check is actually part of the ticket, so if the game goes on, when people leave the stadium, they still have the raincheck because they still have their original ticket.

票根其实是票的一部分，那么如果比赛继续进行，当人们离开体育场时，他们仍然带着票根，因为他们还保留着原来的门票。