3:00用英文怎么说

3:00 的英语表达方式为 "three o'clock" 或 "three in the afternoon/morning"。

其中 "o'clock" 的来源是从古英语 "of the clock" 中衍生而来，意思是“指针在时钟上的位置”。

例句：

"I'll meet you at three o'clock." (我会在三点钟和你会面)
"The store closes at three in the afternoon." (商店在下午三点关门)