I'm going to do my research about analysis of negating suffixes in Japanese newspaper. But I have a big question and want to make sure about Japanese suffixes. Are ーない、－くない、‐ではない、‐なし、‐ぬ、‐ず、 and ‐まい a kind of suffix?
If yes, is there any other negating suffixes besides what I've mention before?
If no, then what are the Japanese suffixes that have a function to negate words?
Please make sure, you are interested in negating suffixes, right?
Assuming you understand what is a suffix at least in English....
Are -ない、-くない、‐ではない、‐なし、‐ぬ、‐ず、 and ‐まい a kind of suffix?
Among these, only -なし can be grammatically called a suffix. It can form derivative nouns that mean "someone/something without ～" or "～-less one".
- 名なし: (noun) an anonymous/nameless person
- 一文なし: (noun) a penniless person
- 能なし: (noun) a dumb, a fool (lit. "one without ability")
All others are grammatically classified as something other than suffix. Basically these are more fundamental parts which are more like English "not", "may not", "is not" or such. Of course you don't call these "suffix", do you?
As @choco said, there are several negating prefixes in Japanese. See: 不 and 非 and 無 and 未 usage difference/rule
－くない and ‐ではない are used with adjectives to reverse their meaning.
－くない is for i adjective and the other one is for na adjective.
馬鹿（ばか）ではない（not stupid）
かしこくない（not smart）
ーない is a suffix to to reverse the meaning of verbs.
食べない（don't eat）
Verbs can be turned into a i adjective （with the "want to -tai" form） then combined with the くない form though.
食べたくない（don't want to eat）
‐ず means doing something without doing something else and is usually followed by に.
食べずに学校行きました。
I went to school without eating.
なし is more like a noun and just means none. It is not used a lot and can be awkward to use.
‐ぬ is basically the old Japanese way of talking and is rarely used except by wise old monks in movies or something. It is used instead of -nai after a verb.
You can add the following, but they are considered archaic:
ざる
http://dictionary.goo.ne.jp/jn/89724/meaning/m0u/%E3%81%96%E3%82%8B/
まじ
http://dictionary.goo.ne.jp/jn/207942/meaning/m1u/%E3%81%BE%E3%81%98/
