は
Meanings
1
topic marker
Marks the topic of the sentence. Pronounced わ.
I am a student.
2
contrast marker
Indicates contrast with another option, stated or implied. Pronounced わ.
I like dogs, but I don't like cats.
3
emphasis marker
Adds emphasis to the preceding word. Pronounced わ.
That is not the case (emphatic).
Usage patterns
- 〈物〉は〈事〉as for [topic], [comment]
As for this book, it's interesting.
- 〈物〉は〜が、〈物〉は〜[thing A] is..., but [thing B] is... (contrast)
I like meat, but I don't like fish.
- 〈動詞〉ては〜emphatic negative condition (used with ない forms)
You mustn't give up.