は vs が: The Difference Between Wa and Ga

Two people can introduce themselves with almost the same sentence. 私は田中です (わたしはたなかです) and 私が田中です (わたしがたなかです) both come out in English as "I'm Tanaka." The first is what you'd say when someone asks who you are. The second is what you'd say when someone walks into the room and asks which person is Tanaka.

That gap is the は and が problem in miniature. English handles it with stress in the voice, so there's nothing on the page to translate, and learners end up guessing. The rules below won't remove the guessing overnight, but they cover most sentences you'll meet. If particles in general are still new, start with our overview of Japanese particles.

Topic and subject aren't the same thing

は marks the topic: what the sentence is about. A decent translation is "as for X" or "speaking of X." が marks the grammatical subject: who or what does the verb, or has the quality the adjective describes.

Very often the topic and the subject are the same person, which is why the two get confused. But a topic doesn't have to be the subject at all:

• 今日は雨です。 (きょうはあめです) It's rainy today. Today isn't doing anything. It's the frame for the comment.
• この本は昨日買いました。 (このほんはきのうかいました) I bought this book yesterday. The book is the object of 買いました, promoted to topic.
• 東京には行ったことがあります。 (とうきょうにはいったことがあります) I've been to Tokyo. Here は sits on top of に.

When は takes over a noun that would otherwise have が or を, those particles vanish. You never write がは or をは. Other particles stay, and は stacks after them, giving には, では, とは and からは.

が introduces, は picks up

The most reliable way to think about the pair is new and old information. が brings something into the conversation for the first time. は talks about something both people already have in mind. Japanese folk tales show it neatly in their opening lines:

昔々、あるところにおじいさんがいました。おじいさんは毎日山へ行きました。
むかしむかし、あるところにおじいさんがいました。おじいさんはまいにちやまへいきました。
Once upon a time, in a certain place, there lived an old man. The old man went to the mountains every day.

First mention, が. Second mention, は. It lines up roughly with "an old man" and "the old man" in English. The match isn't perfect, so treat it as a hint.

The same logic explains why sentences that report something you've just noticed use が. あ、バスが来た (あ、バスがきた) is "oh, the bus is here." 雨が降っている (あめがふっている) is "it's raining." The whole sentence is news, and nothing in it has been set up as a topic yet. Say バスは来た and it sounds like you're contrasting the bus with something else that didn't come.

Question words

A question word is the unknown part of the sentence, so it can't be a topic. When the question word is the subject, it takes が, and the answer does too:

• 誰が来ましたか。 (だれがきましたか) Who came?
• 田中さんが来ました。 (たなかさんがきました) Tanaka came.
• どれが一番安いですか。 (どれがいちばんやすいですか) Which one is the cheapest?
• これが一番安いです。 (これがいちばんやすいです) This one is the cheapest.

When the question word comes later in the sentence, the thing being asked about is already known, so it takes は: これは何ですか (これはなんですか), "what is this?" The answer keeps は as well: これは辞書です (これはじしょです), "this is a dictionary."

That gives you a handy check. In a は sentence, the important part comes after は. In a が sentence, the important part is the noun in front of が. 私が田中です works as an answer to "which one is Tanaka?" because 私 is the missing piece.

は for contrast

は has a second job. It sets one thing against another:

• 肉は食べますが、魚は食べません。 (にくはたべますが、さかなはたべません) I eat meat, but I don't eat fish.
• ひらがなは読めますが、漢字は読めません。 (ひらがなはよめますが、かんじはよめません) I can read hiragana, but I can't read kanji.

The other half of the contrast doesn't have to be spoken. If someone asks whether you like sports and you answer テニスは好きです (テニスはすきです), the listener hears "tennis, I like," with an unspoken "the rest, not so much." This is why swapping が for は can change the mood of a sentence even when the grammar is fine.

Negative sentences lean toward は for the same reason. お酒は飲みません (おさけはのみません), "I don't drink alcohol," is more common than お酒を飲みません, because denying something tends to set it apart from the things you do.

The 象は鼻が長い pattern

One sentence shows up in nearly every discussion of Japanese grammar: 象は鼻が長い (ぞうははながながい). Word for word it's "as for elephants, noses are long," and in normal English, "elephants have long trunks." It has a topic (象) and a separate subject (鼻), each with its own particle.

This is the standard way to describe a part or feature of something, and you'll use it constantly:

The big frame takes は, and the specific thing inside that frame takes が. English usually turns these into "X has Y" or "X's Y is something."

Words that want が where English has an object

"I like cats" has an object in English. In Japanese, 好き is an adjective meaning something close to "liked" or "pleasing," so the cat is its subject: 猫が好きです (ねこがすきです). A group of very common words works this way. If you're about to reach for を with one of them, stop and check this list.

Two related cases are looser. Potential verbs traditionally take が, as in 漢字が読めます (かんじがよめます, "I can read kanji"), but を is also widely used and accepted. The same goes for the たい form: 水が飲みたい (みずがのみたい) and 水を飲みたい both mean "I want to drink water."

And all of these can still switch to は when you're contrasting or making the thing your topic. 猫は好きです is a fine sentence. It just hints that there's some other animal you're less keen on.

Inside a clause, use が

When a small sentence is tucked inside a bigger one, to describe a noun or to say when or if something happens, its subject takes が. は would reach out of the clause and claim the whole sentence as its topic.

• 私が作ったケーキ (わたしがつくったケーキ) the cake I made
• 友達が住んでいる町 (ともだちがすんでいるまち) the town where my friend lives
• 母が来たとき、私は寝ていました。 (ははがきたとき、わたしはねていました) When my mother came, I was asleep.
• 雨が降ったら、行きません。 (あめがふったら、いきません) If it rains, I'm not going.

Change the third example to 母は来たとき、疲れていました (はははきたとき、つかれていました) and 母 becomes the topic of the whole sentence: "my mother was tired when she arrived." With が, she only belongs to the "when" part, and the main clause is free to be about someone else.

Two footnotes. In clauses that describe a noun, が can be replaced by の, so 私の作ったケーキ means the same as 私が作ったケーキ. And clauses joined with けど or が ("but") or with から ("because") are loose enough that は turns up inside them freely, especially the contrastive kind.

A checklist for when you're stuck

Run through these in order and stop at the first one that fits.

1. Is the noun a question word, or the answer to one? Use が.
2. Is it the subject of a clause that describes a noun or sets up a "when" or "if"? Use が.
3. Is it the thing liked, wanted, understood, possible or existing? Use が.
4. Are you reporting something you just noticed, with no topic set up yet? Use が.
5. Are you contrasting it with something, or denying it? Use は.
6. Otherwise, if it's what the sentence is about and the listener already knows which one you mean, use は.

Why this takes so long to feel natural

None of these rules is how Japanese speakers actually choose. They pick by feel, built from years of hearing sentences, and in many cases both particles are grammatical and only the nuance differs. Advanced learners still get corrected on は and が long after they've stopped making other mistakes.

It also helps to remember that real Japanese often uses neither. Once a topic is established, it's left out. Ask 田中さんは学生ですか (たなかさんはがくせいですか, "is Tanaka a student?") and the natural answer is はい、学生です, with no 田中さんは in it. Repeating the topic isn't wrong, just heavy. A lot of beginner は overuse is really a failure to drop the topic, especially 私は at the start of every sentence.

So learn the checklist, then read and listen a lot. Each time a が turns up where you'd have written は, ask which of the reasons above applies. Most of the time one will.

Common questions