英语翻译Do you know what 'promise' means?对么?是means还是mean啊?

问题描述:

英语翻译
Do you know what 'promise' means?
对么?是means还是mean啊?

means
因为括号里的词应该看成是第三人称单数

Do you know the meaning of the word “promise”?
or
Do you know what does the word "promise" mean?
这两个都可以的

为何不写成do you know the meaning of promise?