The Japanese particle na is pronounced like the word "gnaw." It has three different meanings, depending on context:
  1. Asking for or expressing agreement. In this sense, na is similar to the English phrases "right?" or "isn't it?" or "don'tcha think?" Ne is the textbook way to say this in standard Japanese, but na is a more common saying among men in informal situations, and is especially prevalent in the Kansai dialect (where women say it, too). For example:

    bônzu: Kono nôdo, dame ya na.
    dani'i: Na!


    bones: This node sucks, doesn't it?
    dannye: Doesn't it?

    In formal situations, ne is much better.
     
  2. Modifying a noun with an adnoun. Adnouns are basically nouns that turn into adjectives when followed by na. In other words:

    Kono nôdo wa "hentai" to iu. Hentai na nôdo da.
    This node is called "perversion." It is a perverted node.
     
  3. Telling someone not to do something. Stick it on the end of a plain form verb, and it means "don't." Shaberu na!, a common phrase among teachers, means "don't talk!" This is a very direct way to give a command, and should only be used toward subordinates or close friends.