5点半的英语口语是 half past five,
注意:half after five是错误的用法!
P.S. 请帖上面可以写"half after five o'clock"要记得加o'clock!
https://reurl.cc/4oLvMX
Time of day should be spelled out as “four o'clock” or “half after four
o'clock.” Note that “half after” is the most traditional way to indicate
time. However, less formal invitations can use “half past four o'clock” or
“four-thirty.”