In this guide
When I read a Japanese example sentence, I like to imagine someone actually saying it. Who are they talking to, and what does the other person want to know? That’s especially useful with は (wa) and が (ga), two particles: small words that follow a name or noun and help show how it fits into the sentence.
Take “Mina is a teacher.” You could say that while telling a friend about Mina, or because someone has asked which person is the teacher. The English sentence works in both situations. In Japanese, that change in purpose can be a reason to choose a different particle, even though you’re sharing the same fact.
は sets the topic, the person or thing you’re talking about. が marks the subject, the person or thing doing an action or being described. I find those labels easier to understand when there’s a conversation to follow. We’ll look at a few everyday situations here, so you can see what each particle contributes and choose one to fit what you want to say.
Talk about Mina, or answer “who?”
You’re showing a friend a photo. You point to Mina and tell your friend about her.
ミナさんは先生です。
Mina is a teacher.
ミナさんは makes Mina the topic, and 先生です gives a fact about her. Your friend can see who you mean, even if neither her name nor her job has come up in the conversation. は can start an ordinary description like this; no comparison is needed.
The same answer also works when you’re already talking about Mina. If someone asks ミナさんは学生ですか, “Is Mina a student?”, ミナさんは先生です corrects her occupation while continuing to talk about her.
Now you’re trying to find the teacher in a group of people:
だれが先生ですか。
Who is a teacher?
ミナさんが先生です。
Mina is a teacher.
Both sentences describe Mina as a teacher: she is the subject in both. は also makes her the topic, so the sentence gives a comment about her. In the が answer, the sentence supplies the person the question asks for.
Who is a student?
Someone asks だれが学生ですか。 (“Who is a student?”). Ren is a student. How would you answer?
レンさん＿学生です。
Say what is there, or say where it is
が also helps you report a situation you’ve noticed. To say that an object is there, Japanese uses あります. In this pattern, に marks where it is. Imagine you look at a desk and notice a key:
机に鍵があります。
There’s a key on the desk.
鍵が tells us what is there: a key. The sentence doesn’t say that the key is the only object on the desk; が doesn’t always mean “only this one.”
Now someone asks, “Where is the key?” You can make the key the topic and give its location:
鍵は机にあります。
The key is on the desk.
鍵が marks the subject of あります: a key is there. 鍵は instead sets the key as the topic; 机にあります gives its location as the comment. The same verb works with both particles because the sentences present the situation differently.
The key can be yours, one you see every day, and が still reports that it’s there. Mina’s job can be new to your friend, and は still lets you describe her. That’s why I don’t choose by “old information” and “new information” alone.
Where’s the wallet?
Your friend asks, “Where’s my wallet?” You see it in the bag. 財布 means “wallet”; かばん means “bag.”
財布＿かばんにあります。
Use は to make a comparison
You can also use は to draw attention to alternatives. You’re explaining the drinks on a table: the coffee is hot, while the tea is cold.
コーヒーは熱いです。お茶は冷たいです。
The coffee is hot. The tea is cold.
Each は marks one drink for its own comment. Here the two comments make a contrast: one drink is hot and the other is cold.
I try not to make は say more than it does. お茶は冷たいです by itself tells us that the tea is cold. It can invite a comparison, but it doesn’t tell us how warm the other drinks are. You’d need more words for that.
What about the juice?
“Are all these drinks hot?” someone asks. The tea is hot, but you point to the cold juice. ジュース means “juice”; 冷たい means “cold.”
ジュース＿冷たいです。
A topic and a subject can be different things
Sometimes a comment about one thing describes a part of it. Suppose someone asks what a room is like. You want to point out its large windows:
この部屋は窓が大きいです。
This room has large windows.
この部屋は sets the room as the topic. 窓が marks the windows as the subject of 大きいです, “are big.” English naturally says the room “has” large windows; Japanese describes the windows within a comment about the room.
You could instead make the windows the topic:
窓は大きいです。
The windows are big.
Now you’re making a comment about the windows, and the room is no longer named as the broader topic. は and が can work together when the topic and the particular thing being described are different.
What’s the apartment like?
A friend asks, “What’s this apartment like?” You describe its spacious kitchen without comparing it with other parts of the apartment. このアパート means “this apartment,” 台所 means “kitchen,” and 広い means “spacious.”
このアパートは台所＿広いです。
When to choose は or が
Here’s a quick reference to the choices we’ve used. Start with the message you want to give, then look for the matching situation.
| What you want to say | Choice | Example |
|---|---|---|
| Comment on a topic your listener can identify, even at the start of a conversation. | は: topic → comment | ミナさんは先生です。 |
| Answer “who?” or “which one?” when it asks for the subject. | が: supply the subject asked for | ミナさんが先生です。 |
| Report what is there in a scene you’ve just noticed. | が: mark the subject of the report | 机に鍵があります。 |
| Give the location of the thing you’re talking about. | は: thing → location comment | 鍵は机にあります。 |
| Contrast one person or thing with alternatives. | は: mark the item in the comparison | お茶は冷たいです。 |
| Give a plain description of a part while talking about the whole. | whole は + part が | この部屋は窓が大きいです。 |
These are choices about the meaning you want to convey. A は version and a が version can both be grammatical, but they may answer different questions or give a different emphasis. If you’re unsure, add the question or situation around your sentence before deciding.
For your next sentence, picture someone in a photo. Decide whether you’re giving a comment about that person or answering “Who is a teacher?” Then write the sentence that fits that purpose.
You can write that sentence in the Bunpo Check checker for grammar and spelling feedback. A grammar check can help with the wording; you still decide whether the particle fits what you wanted to tell the listener.
About the author
B. Rungswell
B. Rungswell is the editor of the Bunpo Check blog and a native English speaker who has passed JLPT N1. Drawing on many years of life in Japan and experience working at Japanese companies, Rungswell writes practical guides to Japanese grammar for English-speaking learners.