A Japanese language student - I am using this blog as my notebook, if you will, to chart my progress as I continue to learn and recollect information of understanding to read again. So go ahead and start reading.
The formal negative verb for desu is ではありません dewa arimasen.
So to say “it is not, I am not” etc
e.g. It is not a cat. ねこではありません neko dewa arimasen.
It again uses “ha” hiragana for “wa” as the particle.
Reminder: desu is equivalent to “am, is, are”