isn&39;t的完整形式：is not。is not（完全式）=isn&39;t（缩写式）。
isn&39;t（缩写式）= is not（完全式）
isn&39;t
英[ˈɪznt]，美[ˈɪzənt]
例句
1、It isn&39;t too difficult once you get the idea
你一旦弄懂了，就不太难了。
2、Perhaps he isn&39;t coming.
他许不来了。
3、It&39;s past the appointed time. Maybe he isn&39;t coming.
约定的时间都过了，别是他不来了吧？
4、He is not my brother.=He isn&39;t my brother.
