Up for sth. 愿意,并有精力和能力去做……
例句 You know what?It's a long hike to the top of the mountain.Are you sure you're up for it?
你知道么,現在離山頂還有好長一段路呢,你確定你要上么?
I've been working all day long.I'm really tired.I don't think I'm up for going out with you tonight.
我干了一天的活,真的太累了。我想我今晚不能跟你出去了。