USAGE NOTE 用法说明: after an hour and 和 in an hour
Use these phrases to talk about the time in the future when you are going to do something. However, compare the sentences 这两个片语用于谈及将来做某事的时间，但是请比较下列句子: We'll leave after an hour（我们一小时后离开那里） and 和 We'll leave in an hour （我们一小时后离开这里）。
In the first sentence, the speaker is planning how long to stay in a place before they get there. In the second, the speaker is already at a place, and is deciding how much longer to stay there. 在第一句，说话者是在到达某个地方前计划在该地停留多久; 而在第二句，说话者是已经在某个地方并决定在该地停留多久。