many 和much都是形容词,但是他们的比较级more却是副词,为什么呢?

more 是形容词,也是副词,还是名词
如：形容词 意思是：更多的；更大的另外的；多余的
I'm still hungry — can I have some more pudding?我还饿,我可以再要些布丁吗?
There is more food in the kitchen.厨房里还有多余的食物.
如：副词 意思是：更加；越发,经常地；长期地 ,再
He is more intelligent than his brother.他比他哥哥更聪明.
I like football more than swimming.我喜爱足球胜过游泳.
You ought to practice more.你应该经常练习.
The old man doesn't travel any more.这位老人不再旅行了.
如：名词：意思是：较大量,较多量,较多的数目
I'm afraid I've eaten more than enough.我怕我是吃得过多了.