三十

In a sentence

• 我今年三十岁了。

  I am thirty years old this year.

  In this sentence, '三十' indicates the numeral 30, specifying the speaker's age.

• 商店里的这件衣服三十块钱。

  This piece of clothing in the store costs thirty yuan.

  Here, '三十' is used to express the price, showing the monetary value of the clothing item.

• 他花了三十分钟完成了这个任务。

  He spent thirty minutes completing this task.

  In this example, '三十' quantifies time, denoting the duration taken to finish the task.