昨天是星期几英语怎么说

昨天是星期几英语是 "What day of the week was yesterday?" 。

它的来源是从基本的英语句型 "What day is it today?" 变化而来。 "What" 是问句中的疑问词，"day" 是星期几的意思，"of the week" 是指星期几，"was" 是过去式的助动词，"yesterday" 是昨天的意思。

一些英文例句及其中文翻译如下:

What day of the week was yesterday? 昨天是星期几？
Yesterday was a Monday. 昨天是星期一。
Yesterday was not a weekend day. 昨天不是周末。