30 minutes can be referred to as "half an hour" in Engpsh.
The term "half an hour" comes from the concept of dividing an hour into two equal parts, each of which is 30 minutes long.
Examples in Engpsh:
Can you give me 30 minutes of your time?
(你能给我30分钟的时间吗？)
The meeting will last for 30 minutes.
(会议将持续30分钟。)
Note: In everyday conversation, people often simply say "30 minutes" instead of "half an hour."