1.a lot of ,lots of,plenty of 等词组表示许多大量,既可以修饰可数名词也可以修饰不可数名词.比如:a lot of books ,plenty of water.
2.a great deal of ,a large amount of,a little ,little,只能修饰不可数名词.谓语动词用单数形式.例如:A large amount of medicine is needed in that area.
3.a great many ,a large number of ,a great number of,表示许多大量,可修饰可数名词复数.谓语动词用复数形式.
4.many a 可表示许多,但做主语时谓语动词只能用单数第三人称.
例如:Many a scientist has been trying to research into the SARS bacteria.
5.masses of 做主语时谓语动词用复数,a mass of 修饰主语时谓语动词用单数.例如:Masses of work are to be done to welcome the new year.
6.a quantity of ,(large )quantities (of ) 作主语,或其所修饰的名词作主语时,其谓语动词应根据quantity 的单复数形式而定.例如:Large quantities of money are needed to equip the school.
A quantity of story books has been bought for the children.