a great many和a number of的区别

a great many后直接修饰名词, 名词可以有修饰语, 如:
a great many students
a great many young students;
a great many of后主要接：
1. 代词：a great many of them
2. 受冠词修饰的名词：a great many of the students
3. 受these, those修饰的名词：a great many of these students
4. 受物主代词修饰的名词：a great many of my students
5. 受所有格修饰的名词：a great many of Tom's students;
a number of是大量的 等于a lot of一类 后面接名词复数 如:A number of apples are red. 许多苹果是红色的。

后面都是加复数名词。无区别

a great many不可数和a number of可数

a great many 加名词修饰语
a number of 加代词
a great many 和 a number of 都是表示很多的意思，可以通用，后面都是加复数名词
例如：
There’re a number of students reading English in the classroom.
= There're a great many students reading Engilsh in the classroom.
教室里有很多学生在读英语。
a great many后面加of时，a great many of 后主要接：
1. 代词：a great many of them
2. 受冠词修饰的名词：a great many of the students
3. 受these, those修饰的名词：a great many of these students
4. 受物主代词修饰的名词：a great many of my students
5. 受所有格修饰的名词：a great many of Tom's students
首先a great many和a number of同意为：很多,但很显然a great many后只能加可数名词复数,在句中相当于lost of的用法.而a number of则可以修饰可数名词复数和不可数名词.不过要注意的是两者系动词都要用is