In linguistics, an A-not-A question is a polar question that offers two opposite possibilities for the answer. Examples in English are "Are you happy or sad?" and "Are you happy or not?". The answer to the former must be an echo answer, stating the correct alternative ("I am sad"
; however, the answer to the latter can be yes or no in response to the first and more explicitly stated alternative.
Mandarin Chinese frequently uses A-not-A questions and answers them with echo answers, as in these examples:[1]:pp.558-563
Nǐ yào bu yào chī júzi? ("You want not want eat orange?"
Yào. ("Want."
Bu yào. ("Not want."
Tā màn-màn-de pǎo háishi bu màn-màn-de pǎo? ("
S)he slowly run or not slowly run?"
Màn-màn-de pǎo. ("Slowly run."
Bu màn-màn-de pǎo ("Not slowly run."
^ Li, Charles N., and Thompson, Sandra A., Mandarin Chinese: A Functional Reference Grammar, Univ. of California Press, 1981.
http://en.wikipedia.org/wiki/A-not-A_question
Thus to simplify Parmenides - Is it that I exist? (Is it not that I exist?) - two questions that cannot be answered in the negation without affirmation = I do not exist (I do not not-exist.)
Here's a link to some really academic papers on how this works in Mandarin:
http://www.springerlink.com/content/h347q3263r4g7646/
It's a useful way to think about nothingness without concluding that there can only be not-nothingness. Trust me, it's not a trick.
(I actually learned this is a course on "Idea Systems of Chinese Religions" and not in a linguistics class.)