“precisely when” 表示“恰好在……的时候/正是在……之时”,用于强调时间点非常准确,常接一个从句来说明具体发生的时刻。(也可用于加强语气:强调“就是在那一刻”。)
/prɪˈsaɪsli wen/
I’ll call you precisely when I arrive.
我会在我一到达时就立刻给你打电话。
The alarm went off precisely when we were trying to leave quietly, which made everyone look at us.
我们正想悄悄离开时警报恰好响了,结果大家都看向我们。
precisely 来自拉丁语 praecīsus(“切得整齐、精确的”),经法语进入英语,含义发展为“准确地、精确地”;与 when 组合时,常用于强调“时间点的精确对应”。