4:00用英语怎么说

"4:00" in English is commonly expressed as "four o'clock" or simply "four."

The origin of this form of expressing time can be traced back to the use of Roman numerals, where "IV" was used to represent 4. Eventually, the use of "IV" for 4 was pronounced as "four" and the practice of using "o'clock" to indicate the specific time of the hour was added.

Examples:

"I'll meet you at four o'clock." (我会在4点和你见面。)
"What time is it? It's four." (现在几点了？4点。)