The Particle “ga”: Subject, New Information, Emphasis [JLPT N5]
By Nihongo to Japan · Updated July 3, 2026
「誰が来た？」「私が来た！」 — が marks not the topic but the protagonist of the action.
The Particle “ga”: Subject, New Information, Emphasis
The particle 「が」 marks the ‘protagonist' of an action/state, with three main functions: ① subject (the doer): 「猫が魚を食べた」 (the cat ate the fish), 「雨が降る」 (it rains); ② new information/unknown (info the listener doesn't know — a story's debut, a question word as subject): 「むかしむかし、おじいさんがいました」 (long ago, there was an old man), 「誰が来た?」 (who came?); ③ emphasizing the subject (stressing ‘who,' exclusive): 「私がやります」 (I'll do it); plus the object of certain predicates: 「日本語がわかる」 (understand Japanese), 「水がほしい」 (want water), 「ピアノが上手」 (good at piano) — the object of liking/ability/desire/sensation uses が. ⚠️ Key: a question word as subject must use が (誰が来た, ✗ 誰は); the answer also uses が (私が)! ⚠️ Contrast with は: が marks the protagonist (new info), は marks the topic (known).
🧠 Core nuance: marking the ‘protagonist of the action' and ‘new information'
The core is が marks the ‘protagonist' of an action/state, often with a ‘new information' nuance: ① subject (the doer) — marking who does an action, what exists (猫が魚を食べた = the cat ate the fish, 雨が降る = it rains, 花が咲く = flowers bloom, 子供が泣いている = a child is crying); ② new information/unknown — making ‘something the listener doesn't yet know' the subject (a story's debut: 昔々、おじいさんがいました; a question word as subject: 誰が来た? = who came?, 何があった? = what happened?; answering: 私が来た = it was me); ③ emphasizing the subject (exclusive) — stressing ‘this very person/thing' (私がやります = I'll do it, excluding others); ④ the object of certain predicates — the object of liking/ability/desire/sensation uses が (日本語がわかる = understand Japanese, 水がほしい = want water, ピアノが上手 = good at piano, 頭が痛い = headache, 音が聞こえる = hear a sound). ⚠️ Core contrast with 「は」: 「が」 = marks the protagonist/new info (a question word as subject, the answer, a first appearance: 誰が? 私が!); 「は」 = marks the topic/known (私は… = as for me)! ⚠️ Key rule: a question word as subject must use が (誰が来た?, ✗ 誰は); answering a question also uses が (私が来た); describing a scene before your eyes uses が (あ、虹が出た). One of the most important N5 particles.
📌 Three Functions
| Function | Nuance | Example |
|---|---|---|
| subject (doer) | who does/what exists | 猫が魚を食べた |
| new info/unknown | info the listener doesn't know | 誰が来た? |
| emphasizing subject (exclusive) | this very one | 私がやります |
| object of certain predicates | liking/ability/desire/sensation | 日本語がわかる |
💬 Example Sentences
- 誰が音楽が好きですか?(Who likes music?) — question word as subject (must use が)
- 日本語がわかりますか?(Do you understand Japanese?) — object of ability
- むかしむかし、おじいさんがいました。(Long ago, there was an old man.) — new info (story debut)
- 「誰が発表しますか?」「私が発表します。」(Who presents? I will.) — answering (use が)
- 富士山が見える。(Mt. Fuji is visible.) — object of sensation/scene before one's eyes
🔄 Compare: が vs は (the most important contrast)
| Item | が | は |
|---|---|---|
| marks | protagonist/new info (unknown) | topic/known |
| question word as subject | must use が (誰が来た?) | ✗ 誰は |
| answering a question | 私が (it's me) | — |
| focus | on the subject (before が) | on the predicate (after は) |
⚠️ Common Mistakes
- A question word as subject must use が: 誰が来た? (✗ 誰は来た?); 何が起きた? (a question-word subject uses が).
- Answer with が: when asked ‘who,' answer ‘私が' (✗ 私は), because it's new info.
- The object of certain predicates uses が: liking/ability/desire/sensation — 日本語がわかる, 水がほしい, ピアノが上手 (✗ を).
- が vs は: が = protagonist/new info (focus before); は = topic/known (focus after).
💡 Nuance & When to Use
The particle 「が」 marks an action/state's ‘protagonist,' with three functions: subject (猫が魚を食べた), new information/unknown (誰が来た?, おじいさんがいました), emphasizing the subject (私がやります); the object of certain predicates (liking/ability/desire/sensation) also uses が (日本語がわかる, 水がほしい). ⚠️ Contrast with は: が = protagonist/new info (a question-word subject must use が, the answer uses が), は = topic/known. One of the most important N5 particles — memorize it.
🎯 JLPT Exam Tips
- N5 core: が = subject (猫が), new info/unknown (誰が来た?, おじいさんが), emphasizing the subject (私が), object of certain predicates (日本語がわかる/水がほしい).
- Most important rule: a question word as subject must use が (誰が来た?, ✗ 誰は); answer with が (私が).
- が vs は: が = protagonist/new info (focus before); は = topic/known (focus after).
🖊️ Practice Quiz
Q1. 「___音楽が好きですか？」Fill the blank.
(A) 誰が (B) 誰は (C) 誰を (D) 誰に
Q2. 「日本語___わかりますか？」Which particle is correct?
(A) を (B) は (C) が (D) に
Q3. 「むかしむかし、おじいさん___いました。」(a story's opening) Which is correct?
(A) は (B) が (C) を (D) で
Q4. A friend asks 「誰が発表しますか？」 and you want to say “it's me.” How do you answer?
(A) 私は発表します。
(B) 私を発表します。
(C) 私が発表します。
(D) 私に発表します。
Q5. Which sentence's 「が」 has a different use from the other three?
(A) 猫が魚を食べた。
(B) 富士山が見える。
(C) 行きたいが、忙しい。
(D) 誰が来ましたか？
Answer Key
1. (A) 誰が ── a question word (誰) as subject must use が, not は. 誰が音楽が好きですか = who likes music?
2. (C) が ── the object of 「わかる」 uses が, not を.
3. (B) が ── a first appearance in a story uses が (new information): おじいさんがいました.
4. (C) 私が発表します ── answering a question-word subject uses が (私が), because it's new info.
5. (C) ── (A)(B)(D) are the subject-marking が; (C) 行きたいが is the adversative conjunction が (but).