意思都是“很多，大量”只能修飾可數名詞的：a large/ great/ good number of, a good/ great many, dozens of, scores of, quite a few 只能修飾不可數名詞的：a great deal of, a large amount of, quite a little,a large sum of 既可修飾可數也可修飾不可數名詞的：plenty of, a lot of, lots of, a large quantity of, a good supply of但是a number of不能修飾不可數名詞。

只能修飾可數名詞的：a large/ great/ good number of, a good/ great many, dozens of, scores of, quite a few 只能修飾不可數名詞的：a great deal of, a large amount of, quite a little,a large sum of 既可修飾可數也可修飾不可數名詞的：plenty of, a lot of, lots of, a large quantity of, a good supply of但是a number of不能修飾不可數名詞。

以下是一些常用的短語的用法：

a lot of/ lots of + 可數名詞複數/不可數名詞。there is a lot of water in the pool. 池子裡有很多的水。

plenty of +可數名詞複數/不可數名詞。there are plenty of cars on the freeway. 高速路上有很多的汽車。

many a + 可數名詞單數，謂語動詞用單數形式。many a scientist has gone to the lonely island. 不止一個科學家去過那個偏僻的小島。