如果某种语言做主语,谓语用单数还是复数

一种语言作主语时,谓语动词用单数.但当其做人民讲时,谓语动词用复数.
例如：
The Chinese is very difficult to learn.
A lot of foreigners said that the Chinese are so warm-hearted.
a number of 后一般加可数名词,如：a number of people,a number of books 因此后面的谓语动词要用复数形式.
例如：
There are a number of students in the room.
a number of 一些
the number of 指数量.
比较下列句子：
The number of the students is increasing.
学生的数量在增长.
A number of students are absent today.
今天一些学生缺席.
不知你是否明白了.