There's a particle in Japanese that appears everywhere but seems to mean two completely different things — が. Sometimes it marks the subject, sometimes it means "but." Confusing? Not really. The trick to telling them apart is dead simple.
Face 1: Case Particle が — Marking the Subject
The most fundamental function of が is marking the subject — who does the action, who exists there:
| Japanese | English | が marks |
|---|---|---|
| 吉田さんがここへ来ます。 | Yoshida is coming here. | 吉田さん |
| 誰がいますか。 | Who is there? | 誰 |
| 机の上に本があります。 | There's a book on the desk. | 本 |
Where does this が appear?
Case particle が always comes right after a noun:
Noun + が + verb/adjective
This is the key clue — if が follows a noun, it's the subject marker.
How is が different from は?
In short:
| は | が | |
|---|---|---|
| Function | Marks the topic (known info) | Marks the subject (new info / emphasis) |
| Feel | "Speaking of A..." | "It's A who...!" |
田中さんは来ます。 → As for Tanaka, he's coming. (neutral statement) 田中さんが来ます。 → It's Tanaka who's coming! (emphasis / new information)
When answering "Who's coming?", you must use が because the answer is new information:
Q: 誰が来ますか。 → Who's coming? A: 吉田さんが来ます。 → Yoshida is coming.
Face 2: Conjunctive が — Meaning "But"
The second identity of が is connecting two sentences to express contrast:
| Japanese | English |
|---|---|
| おいしいですが、高いです。 | It's delicious, but it's expensive. |
| 日本語は難しいですが、おもしろいです。 | Japanese is difficult, but it's interesting. |
How to tell the two apart?
Look at what comes before が:
| Before が | Identity | Meaning |
|---|---|---|
| Noun | Case particle | Marks the subject |
| Verb / adjective / です | Conjunctive particle | "But" |
吉田さんが来ます。 → Noun + が = subject marker おいしいですが、高いです。 → です + が = "but"
That's it: Noun + が = subject. Predicate + が = "but."
Common Uses of Subject-Marking が
1. Existence Sentences (あります / います)
The thing that exists is marked with が:
教室に学生がいます。 → There are students in the classroom. 机の上に本があります。 → There's a book on the desk.
2. Question Words as Subject
When a question word (who/what) is the subject, it must take が:
誰が来ますか。 → Who is coming? 何がありますか。 → What is there?
3. Objects of 好き / 嫌い / 上手 / 下手
With words for liking, disliking, being good at, or being bad at, the object takes が:
私は日本語が好きです。 → I like Japanese. 田中さんは英語が上手です。 → Tanaka is good at English.
Here は marks the topic (I / Tanaka), and が marks the object of 好き / 上手 (Japanese / English).
Wrap-Up
- Noun + が = case particle marking the subject ("It's A who...")
- Sentence + が = conjunctive particle meaning "but"
- How to tell: look at what comes before が — noun or predicate
- Existence sentences (あります/います) mark the subject with が
- Question words as subjects must take が
- Objects of 好き/嫌い/上手/下手 take が
Practice
Q1. What does が mean in 「おもしろいですが、難しいです」?
Show Answer
Here が is a conjunctive particle meaning "but." It follows です (a predicate), not a noun.
Full meaning: It's interesting, but it's difficult.
Q2. Answer the question: 「誰が来ますか。」 — Tanaka is coming.
Show Answer
田中さんが来ます。
When answering "who" questions, the answer is new information and must be marked with が. You cannot say 田中さんは来ます here, because は is for known/established topics.
Q3. Fill in the particle: 「私は日本語＿好きです。」
Show Answer
私は日本語が好きです。
The object of 好きです takes が. は marks the topic (私), が marks the object of liking (日本語).