isn't       
uk/ˈɪz.ənt/ us/ˈɪz.ənt/
 (is not的缩略形式)
short form of is not
  He isn't coming until tomorrow. 他到明天才能来。 
 - More examples
- It isn't easy being a parent.
- "Is there any more soup?" "No, I'm afraid there isn't any left."
- He's getting old and his hearing isn't very good.
- It's rather cold today, isn't it?
- Leave daddy's camera alone - it isn't a toy!