[求]"what a" 和 "how a"

What + a + 形容词 + 名词单数 (+ 主语+动词)！
What a beautiful girl she is!

What + 形容词 + 名词复数 (+ 主语 + 动词)！
What beautiful girls they are!

What + 形容词 + 不可数名词 (+ 主语 + 动词）！
What delicious milk it is!

How + 形容词/副词 (+ 主语 + 动词）！
How beautiful this girl is!

以上有点麻烦，简单记：
把感叹句从后面把主语和谓语（句子）挑出，然后看前面的感叹部分，若有名词，就用what；若无，就用how。但是注意单数时候：what a careful student she is! = How careful a student sh is!

练习：
_____nice it is today!
_____ a nice day it is today!
_____ ugly animals they are!
Keys: How; What: what

What a big box it is! == How big the box is!
What nice weather it is!== How nice the weather is!
What clean rooms they are!== How clean the rooms are!

what a 是说物品类的 比如 what a sunny day 多么晴朗的天气啊
how 是指方式 方法 怎样之类的，一般不会说how a。。。
真的有，就是how a man is supposed to change，这里a是修饰man的

问用法 还是..?