wa

Particle

1. indicates sentence topic

あの いぬはしっぽが みじかい。
ano inuwa shippoga mijikai.
That dog has a short tail.
Particle

2. indicates contrast with another option (stated or unstated)

かぜには大食 たいしょく、熱 ねつには小食 しょうしょく
kazeniwa taishoku netsuniwa shōshoku.
Feed a cold and starve a fever.
Particle

3. adds emphasis

はははぜったいに早起 はやおきはしない。
hahawa zettaini hayaokiwa shinai.
My mother never gets up early.