我朋友下午四点才到用英语怎么说

"My friend arrived at four o'clock in the afternoon"可以用英语表达为"My friend arrived at 4pm"。
"pm"是英文"post meridiem"的缩写，意思是"下午"。
例句1:
My friend arrived at 4pm.
我的朋友在下午4点到。
例句2:
I'll meet you at the park at 4pm.
我会在下午4点在公园见你。
例句3:
The meeting is scheduled for 2pm.
会议安排在下午2点。