[译] 在这样一个晚上他会到哪里去呢？
[误] Where must he have gone on such a night?

[正] Where could he have gone on such a night?
[注] could和不定式的完成时连用,用来谈已发生过的事,表示一种推测,用于疑问和否定句中,而must用于这种场合,只在肯定句中使用。