感叹句通常是由what,how来引导
what后面只加名词,而how后面可以加形容词,副词
就拿你的句子举例子：the room is big
可以改为
how big the room is 或者 what a big room 或者what a big room it is 后面那个it is 可以省略
不难看出句型就是：
how+形容词或副词+陈述语序
what +名词+ 陈述语序
这当然是最基本句型,还可以做变换,比如名词前面再加上形容词修饰变成：what+形容词+名词,甚至再加上不定冠词变成：what+a/an +形容词+名词,注意,这里的中心词还是名词,因为what后面只跟名词
其余的句子：
it is a very interesting film
改为：how interesting the film is
what a interesting film it is
my dog is very smart
改为：how smart my dog is
what a smart dog
we have a good teacher
改为：how good a teacher we have
what a good teacher we have
注意区分这两句,前面的中心词在good,how修饰good,后面那句的中心词在teacher,冠词a,形容词good还有感叹词what都修饰teache
