how是个疑问副词,what是个疑问代词.在它们引起的句式中,有时可以互相换用,来表达相同或相似的意思.
一、问天气：How…?=What…like?如：
How was the weather yesterday?昨天的天气怎么样?
What was the weather like yesterday?
二、征求意见或建议：How about…?=What about…?如：
How about going skating?
What about going skating?去滑冰怎么样?
三、问年龄：How old…?=What…the age…?你多大岁数了?
四、问看法：How…like…?=What…think of/about…?如：
How do you like this film?你认为这部影片怎么样?
What do you think of this film?
五、问价钱：How much…?=What…the price 价钱）of…?如：
How much is the book?
What’s the price of the book?这书多少钱?
六、“how／what+可数名词单数”构成感叹句：How + adj.+ a/ an+ n…!=What + a/an +adj.
+n.…!如：
How clever a girl she is!她是个多么聪明的女孩子啊!
What a clever girl she is!
七、“how/what+可数名词复数或不可数名词”构成感叹句,句子结构有所不同,汉语意思也稍有差异.如：
How high the mountains are!这些山多高啊!
What high mountains they are!多高的山啊!
当然,有些由how引起的感叹句是不能用what进行转换的,如下列句子中的how不宜换用what.
How fast he is running!他跑得多快啊!
How time flies!光阴似箭!