(postposition, Japanese)
The Japanese postposition (like a
preposition except after a word) "wa" is the topic
marker, which identifies the topic (duh) of the sentence. The literal meaning is "As for (noun)." Usually the topic and the subject are the same thing, but only if the topic has already been introduced; otherwise, you use the subject marker "ga." Additionally, "wa" can be used to indicate contrast or emphasis of the subject. The way "wa" is being used depends on context and
intonation.
Topic: Watashi wa koukousei desu. ("I am a high school student.")
Contrast:
Biiru wa nomimasu ga,
wain wa nomimasen. ("I drink beer, but I don't drink wine.")
As an aside: Wa is not a verb; verbs are always at the end of a sentence in Japanese. Wa is not the Japanese
copula, "desu" is; all wa does is tell you what the hell is being talked about. Don't be stupid and think of it any other way.