In Japanese grammar, what is the difference between wa (は) and ga (が) particles?
The Japanese particle 'wa' (は) is employed to indicate the topic of a phrase, while 'ga' (が) marks the protagonist of a phrase.
The particle 'wa' (は) is utilized to present a theme that is already known or established, and to show that the orator is varying the concentration of the dialogue. It is likewise employed to point out the usual theme of a piece of writing. For instance, in the phrase Kore wa watashi no hon desu (これは私の本です), 'wa' signals that the topic of the phrase is this.
The particle 'ga' (が) is utilized to introduce a new topic or subject, and to emphasize the protagonist of a clause. It is also utilized to signify that the orator is making a declaration about the subject. For example, in the phrase Taro ga hon o kaimashita (太郎が本を買いました), 'ga' signals that the subject of the phrase is Taro and that the phrase is making a statement about him.
Further, 'wa' can be employed to signify a contrast between two topics, while 'ga' is utilized to signify a comparison between two topics. For example, in the phrase Taro wa watashi yori atsui desu ga, watashi wa Taro yori tsumetai desu (太郎は私より暑いですが、私は太郎より冷たいです), 'wa' indicates a contrast between Taro and I, while 'ga' indicates a comparison between the two.
All told, 'wa' (は) is employed to introduce a theme and to signify a contrast between two topics, while 'ga' (が) is utilized to introduce a new protagonist and to indicate a comparison between two topics. By utilizing these two particles correctly, you can readily make your point lucid in Japanese.