the weather is very cold today

What
由what,how引导的感叹句的构成形式、用法及区别
　　感叹句是表示喜、怒、哀、乐以及惊异等感情的句子.句末用感叹号“!”,读时用降调,感叹句往往由what或how引导,what修饰名词,how修饰形容词,副词或动词.
1.what引导的感叹句：
　（1）what + a/an +形容词+单数可数名词+陈述句（主语+谓语）
　　　What a beautiful city it is!
　　　What an interesting story she told!
　（2）what+形容词+复数可数名词/不可数名词+陈述句（主语+谓语）
　　　What expensive watches they are!
　　　What terrible weather it is!
2．How引导的感叹句：
　（1）How+形容词/副词+陈述句（主语+谓语）
　　　How cold it is!
How hard he works!
　（2）How+陈述句（主语+谓语）
　　　How he loves his son!
How I miss you!
　（3）How+形容词+a/an+单数可数名词+陈述句（主语+谓语）
　　　How tall a tree it is!
（4）上述两种感叹句可以互相转换.例如：
What a clever boy he is!→How clever the boy is!
What a cold day it is!→How cold it is!