英语中 什么时候不加限定词?

首先要搞清楚,是修饰可数名词或不可数名词,而不是单数或复数名词.可数名词都有复数形式,而不可数名词没有复数形式.
a large deal of、a plenty of和a good supply of 在多数情况下修饰不可数名词,如：a plenty of water,a geat deal of time,不过它们也可以修饰可数名词,如a plenty of men.
a quantity of在多数情况下修饰可数名词,如a quantity of boxes,不过也可修饰不可数名词,如a quantity of milk.
quantities of与上述的一样
一、只能修饰可数名词的词语有:
many,many a(n),a good / great many,a (great / large) number of,scores of,dozens of等.例如:
Scores of people went there in the first few days after its opening.
开张后的头几天,很多人去了那儿.
I have been there dozens of times.
我已去过那儿很多次了.
There’re a number of students reading English in the classroom.
教室里有许多学生在读英语.
Many a student has(=many students have)visited the Great Wall.(谓语动词用单数)
很多学生都游览过长城.
In winter,a good many animals sleep under the snow.
冬天很多动物在雪下冬眠.
注意:many所修饰的复数名词前若有限定词,many 后面要接of,表示“……中的很多”.例如:
A great many(of the) graduates have found jobs.
毕业生中很多人已经找到了工作.
二、只能修饰不可数名词的词语有:
much,a great deal of,a great / large amount of等.例如:
Is there much water in the bucket?
桶里有很多水吗?
He always has a great amount of work to do.
他总是有很多工作要做.
三、既能修饰可数名词又能修饰不可数名词的词语有:
a lot of,lots of,plenty of (以上三个词语后谓语动词的数依of 后的名词的单复数而定),a great / large quantity of (其后谓语用单数),quantities of (其后谓语用复数).例如:
There is still lots of snow in the garden.
花园里还有许多雪.
There is plenty of rain here.
这儿的雨水很多.
A great quantity of flowers was placed in the hall.
大厅里放了很多鲜花.
There are large quantities of food in the cupboard.
橱柜里有许多食物.
在所有这些表示“很多”的词语中many,much 是最常用的词,它们既可以用于肯定句,也可以用于疑问句和否定句.例如:
Are there many people in the street?
街上有很多人吗?
There isn’t much time left.
剩下的时间不多了.
其它的词语都用于肯定句,日常会话中常用lots of,a lot of 或plenty of; 正式文体中常用 a great many,a (large) number of,a great deal of,scores of 或 dozens of 等.但若肯定句中有too,so,as,very或how 等词修饰时,则必须使用 many,much.例如:
The number of the people who lost their homes reached as many as 250,000.
无家可归的人数多达250,000人.
There is too much work to do.
要做的工作太多了.