purpose有单数吗……

【专家解说】：purpose
词义为：意志；毅力；决心 时不可数
其它两个名词词性时是可数名词

词义与例句来自《柯林斯高阶英汉双解词典》

1. N-COUNT 意义；用途 The purpose of something is the reason for which it is made or done.
The purpose of the occasion was to raise money for medical supplies...
那次活动是为筹集资金购买医药物资。
Various insurance schemes already exist for this purpose.
已经有各种保险计划可以实现这一目的。
...the use of nuclear energy for military purposes...
核能在军事上的运用
2. N-COUNT 目标；目的 Your purpose is the thing that you want to achieve.
They might well be prepared to do you harm in order to achieve their purpose...
为达成自己的目的，他们说不定已经做好了伤害你的准备。
His purpose was to make a profit by improving the company's performance.
他的目标是通过提高公司的业绩来实现盈利。
3. N-UNCOUNT 意志；毅力；决心 Purpose is the feeling of having a definite aim and of being determined to achieve it.
The teachers are enthusiastic and have a sense of purpose.
教师们很热情并且很有决心。