thirty minutes：30分钟；

thirty-minute：30分钟的。

thirty minutes只是单纯的指30分钟，如果做定语的话要加s；thirty-minute相当于形容词，直接做定语。

扩展资料

An application will take approximately thirty minutes to process.

签证过程大概需要三十分钟左右。

Study for thirty minutes every day instead of two hours once a week.

一周学两个小时不如每天学半个小时。

Could we keep our room for about thirty minutes after check out time?

结账后我们的房间还能保留三十分钟吗？

More than thirty minutes have passed since I gave an order.

自从我提出要求后已过了三十多分钟了。

Office isn't supposed to close for another thirty minutes.

30分钟内办公室不会关门。