1、many、a great/good many?、a great/large number of?、scores of、dozens of和?(quite) a few,?这类“许多”修饰作主语的名词时，只能修饰名词复数形式，谓语动词用复数。
There are a great/good many English books in our school library.
2、the number of + n?（可数名词复数）?表示"....的数目”,用它做主语时，谓语用单数
The number of the students in our class is 55.
3、既可以修饰可数名词复数，?又可以修饰不可数名词a lot of?、lots of?、plenty of?、supplies of?，a great/quantity of?、great/large quantities of。
He has got a lot/lots of questions to ask.
4、只能修饰不可数名词的“许多”?有：much、a great / good deal of?和a large amount of?，这类“许多”修饰主语名词时候，?谓语用单数。
I don't know they gave us much help.
5、a great deal?做名词词组和副词词组，也表示“大量，许多”，还可以修饰比较级，表示程度。
At the end of the year there was a great deal to do.年底有很多事情做。
6、many a /an +?单数可数名词也表示许多，这个短语作主语时谓语用单数。
Many a girl in our class has learned to swim.
