首先我们来看下the number of和the amount of的大致意思：
the number of：词性为短语，the number of 表示数量的多少，后接可数名词复数形式。
the amount of：词性为短语，the amount of 表示事物的数量或程度，后接不可数名词。
通过下面的表格我们了解下the number of和the amount of的含义、发音和用法
接下来让我们看下the number of和the amount of的用法区别：
1.词性：the number of 是短语，the amount of 是短语
例子：
- The number of students in the class is 30.
(The number of students in the class is 30.)
- The amount of water in the bottle is enough.
(The amount of water in the bottle is enough.)
2.名词形式：the number of 后接可数名词复数形式，the amount of 后接不可数名词
例子：
- The number of cars in the parking lot is increasing.
(The number of cars in the parking lot is increasing.)
- The amount of sugar in the recipe should be reduced.
(The amount of sugar in the recipe should be reduced.)
3.含义：the number of 表示数量的多少，the amount of 表示事物的数量或程度
例子：
- The number of books on the shelf is impressive.
(The number of books on the shelf is impressive.)
- The amount of pollution in the city is alarming.
(The amount of pollution in the city is alarming.)
4.发音：the number of 的英式发音是ðə ˈnʌmbər ɒv，美式发音是ðə ˈnʌmbər əv；the amount of 的英式发音是ðə əˈmaʊnt ɒv，美式发音是ðə əˈmaʊnt əv
例子：
- Please tell me the number of participants in the event.
(Please tell me the number of participants in the event.)
- The amount of time we spent on this project is significant.
(The amount of time we spent on this project is significant.)