1、30的英文翻译是thirty，音标：英 [ˈθɜ:ti]，美[ˈθɜ:rti]，n. 三十；adj. 三十的，三十个的；num. 三十，三十个。

2、[例句]There were at most thirty people in the room.屋里顶天儿三十个人。