助詞N5
〜が
subject/object marker
Structure
N + が + V/Adj
Explanation
Marks the subject of an action or state, and the object of desire/ability/likes. Contrast with は: が emphasizes subject (new info), は emphasizes topic (known info).
Examples
雨が降っています。
It is raining.
私は猫が好きです。
I like cats.
Note
が emphasizes subject; は emphasizes topic. Existence uses が. Question word subjects use が.