Ga: subject marker and Wa: topic marker

[DingoEnderZOE2]

What exactly are the difference between them? And when are they used? I need an explanation on this.

 

[lexico]

What exactly are the difference between them? And when are they used? I need an explanation on this.

General use:

1. predicate=link-verb -> always use "wa"
e.g. Kore-wa hon desu.

2. predicate=verb of existence
2.a. affirmative -> personal pronoun takes "wa"
e.g. Watashi-wa i masu.

2.b. affirmative -> non personal pronoun takes "ga"
e.g. Sensei-ga i-masu.

2.c. negative -> subject takes "wa"
e.g. Hon-wa ari-masen.

3. interrogative subject (pronoun or adj.) always takes "ga"
e.g. Dore-ga hon desu-ka?
but Hon-wa dore desu-ka?

4. when answering a question always repeat the same particle used in the question.
e.g. Kore-ga hon desu.
but Hon-wa kore desu.

Particular use: reversing "wa" and "ga" particularly emphasizes the subject.
e.g. Hon-wa arimasu. "As for the book, there it is."
e.g. Watashi-ga i-masu. "It is I who am here."

日本語四週間 Colloquial Japanese in Four Weeks, Yosio Ogawa, Jun'ichi Sato, 1963, pp.54-55

 

[Damicci]

Wow this makes alot more sense as I get this confused a lot too.