it is not缩写形式是it is not= its not= it isnt。
it isnt 通常只用于后面只有一两个词的短句,尤其是后面什么都没有的省略句,如It is your fault!—No,it isnt!
而it\'s not 既可以用在这样的.句子里,也可以用在长句里,如
It \'s not difficult to understand this sentence.
总之,在长句里,多用it\'s not,在短句里,用it isn\'t 还是 it\'s not,很大程度上存在对上一句的呼应因素.
尚典岩板家居
