a great deal可单独使用，也可以用在形容词或副词的比较级前，表示“大量；许多”；而a great deal of只能用在不可数名词前，表示“大量的”。如：

We learned a great deal from them. 我们从他们那里学到很多东西。
He ran a great deal faster than I. 他跑得比我快多了。
He has given me a great deal of help. 他给了我很多帮助。

     英语中有很多短语表示“大量；许多”，根据性质可分为以下三类：

1. 修饰可数名词的有：a good / great many, a large / great number of, scores of等，谓语动词用复数形式。如：
A great / good many words and expressions have come into the language from American English.
这门语言吸收了美国英语中的许多单词和短语。
There were scores of boxes, all waiting to be checked and loaded. 大批的箱子等着检验后装运。

2. 修饰不可数名词的有：a large amount of等，谓语动词用单数形式。如：
He has spent a large amount of money on his new house.
他在新房子上花费了许多钱。

3. 既能修饰可数名词，又能修饰不可数名词的有：a lot of, lots of, plenty of等，谓语动词根据被修饰的名词是可数还是不可数来决定单复数形式。如：
There are a lot of / lots of people in that room.
那个房间里有许多人。
There’s a lot of / lots of rice in the bag.
那只口袋里有许多大米。
There are plenty of eggs in the fridge.
冰箱里有足够的鸡蛋。
Don’t worry about it. We have plenty of time.
不要着急，我们有充裕的时间。

【例题】从A、B、C、D四个选项中，选出可以填入空白处的最佳选项。
1. They spent ______ money on the new hospital.
A. a great deal       B. a good deal of  
C. a great many      D. a large number of
2. He possesses ______ books.
A. plenty of       B. very much  
C. a great deal of      D. an amount of

Key: 1. B  2. A