which one is correct?

這個是特別的用法, 只要前後對稱就Ok!

所以第二句係正確的。

The more beautiful the hat is, the more expensive it is.
(The more + comparative + n + verb/ verb-to-be, the more + comparative + n + verb/ verb-to-be)

其他例句:

The Higher You Climb, The More You Pay
www.econedlink.org/lessons/index.cfm?lesson=EM586

如果某D adjective不用加more就可以變做comparative, 就不要加more, e.g. safer, higher, longer, prettier, lazier, harder ... 。


圖片參考：http://tw.yimg.com/i/tw/ugc/rte/smiley_1.gif


2008-08-11 18:25:50 補充：
以下o禁都一樣可以架, 請參考:

The more you use, the more you'll have to pay. (water)
www.lasvegassun.com/news/2008/apr/08/water-more-you-use-more-youll-have-pay/

The more you pay, the less you get. (investment)
http://funp.com/t251562#p=251562

2008-08-12 14:39:16 補充：
你好! neo7friend

More examples:

The more transparent the jade is, the more precious it is. 玉器越是通透, 越是珍貴。

The fewer blemishes the jade has, the rarer it is. 玉器越少瑕疵, 越是罕有。

2008-08-12 14:53:35 補充：
The more you expect, the more disappointed you may be. 希望越大, 失望越大。

The more knowledgeable you are, the more confident you will be. 越有知識, 越有信心。
(or The more knowledge you get, the more confidence you gain)

2008-08-12 14:54:25 補充：
Adjustment: confidence > self-confidence

actually, I don't know whether I should put a "is" at the end of the first sentence

the two sentant is wrong"
the correct answer is:
the most beautiful is the hat,the most expensive is it.