When I want to ask whether or not something I have is what I think it is, I can't figure out exactly what to say.

> これは梅じゃないの? (Rising intonation)
> 
> Is this not a plum?

> これは梅じゃないね。(Falling intonation)

> This isn't a plum, right?

How could I say something like 

> "This isn't a plum?!" (With a sense of surprise)

> "Isn't this a plum?"

[For a different example, here is the following from よつばと.][1]


[Which is translated officially to this.][2]


  [1]: https://i.sstatic.net/lg3Av.png
  [2]: https://i.sstatic.net/AKnIc.png

In my mind, the translation is "Aren't I dead?" I guess I don't know if I'm being semantic or not, sorry.