在晚上用英文表达是：at night；

at：prep. 在(某时间或时刻); 在(学习或工作地点); 在(某处)。

night：n. 夜; 夜晚; 晚上，夜晚(夜里就寝前的一段时间); (举行盛事的)夜晚; …之夜。

相关介绍

I started to feel afraid of going out alone at night.

我开始害怕夜间单独外出了。

A red sky at night often indicates fine weather the next day.

夜空呈红色往往预兆第二天天气晴朗。

These animals only come out at night.

这些动物只在夜晚出来。

Is it safe to walk the streets alone at night?

夜间独自一人在大街上行走安全吗？

It's not safe to walk the streets at night.

夜间在街上走不安全。

They insist on playing their music late at night.

已是深夜，他们却依然在放音乐。