Wait a second, is [n''t] an English word? Or should be n't ?
@Sphinx "n't" is a short form of "not".
It's technically a word.
@Sphinx it's a bit ironic for me to explain english when i couldn't even write in english without a typo 
Technically, this isn't an English language test, so as long as people in the conversation understand each other.
Everyone makes mistakes.
@Sphinx
You can use it however you want Depend on the context.
But accordung to my experience on a formal type of conversation people will generally avoids using "n't" as an addition to the "is, are, were, would, do, etc" since it sometimes cause confusion (implying that people are often biased towards what accent they used to hear).