か Particle: Asking Questions and Saying 'Or' in Japanese
What it means
か is the all-purpose question particle. Its main job is simple: tack it onto the end of a statement and the statement becomes a yes/no question — no word order changes, no special verb. The same little particle also links two nouns to mean "or", and it teams up with question words (だれ, なに, どこ) to create indefinite words like "someone" and "something."
ヤッタンは学生ですか。
ヤッタンは がくせいですか。
Is Yattan a student?
先生はコーヒーかお茶を飲みますか。
せんせいは コーヒーか おちゃを のみますか。
Does the teacher drink coffee or tea?
Two か here: 'coffee or tea' and the final question か.
だれかいますか。
だれか いますか。
Is someone there?
How to form it
| Use | Pattern | Example |
|---|---|---|
| Question | sentence + か | これはペンですか (Is this a pen?) |
| "Or" (nouns) | A か B | コーヒーかお茶 (coffee or tea) |
| Indefinite | question word + か | だれか (someone), なにか (something) |
In writing, a question ending in か usually takes a regular full stop (。) rather than a question mark, though casual writing often adds ？ too.
Asking questions with か
Take any plain statement and add か to the end. Nothing else moves:
モチは元気ですか。
モチは げんきですか。
Is Mochi doing well?
明日、学校に行きますか。
あした、がっこうに いきますか。
Are you going to school tomorrow?
To answer, start with はい (yes) or いいえ (no):
はい、行きます。いいえ、行きません。
はい、いきます。いいえ、いきません。
Yes, I'm going. No, I'm not going.
Casual questions often drop か
In casual speech, Japanese frequently leaves か off and just uses rising intonation instead. This is very common between friends:
ヤッタン、行く？
ヤッタン、いく？
Yattan, are you going?
Casual: no か, rising tone marks the question.
これ、おいしい？
これ、おいしい？
Is this tasty?
Adding か here (行くか？) can sound blunt or rough among friends, so plain rising intonation is safer in casual talk. In polite (です/ます) speech, keep the か.
"A or B" with か
Place か between two nouns to offer a choice:
ヤッタンの弟は犬か猫を飼いたいです。
ヤッタンの おとうとは いぬか ねこを かいたいです。
Yattan's brother wants to keep a dog or a cat.
月曜日か火曜日に会いましょう。
げつようびか かようびに あいましょう。
Let's meet on Monday or Tuesday.
This か connects nouns. To list nouns as examples ("things like A and B") rather than a choice, you'd use 〜や instead.
Question word + か = "some-"
Attach か to a question word and it stops being a question — it becomes vague and indefinite:
なにか食べましたか。
なにか たべましたか。
Did you eat something?
なに (what) + か = something.
どこかへ行きたいです。
どこかへ いきたいです。
I want to go somewhere.
いつかまた日本へ行きます。
いつか また にほんへ いきます。
Someday I'll go to Japan again.
The most common ones:
| Question word | + か | Meaning |
|---|---|---|
| だれ (who) | だれか | someone |
| なに (what) | なにか | something |
| どこ (where) | どこか | somewhere |
| いつ (when) | いつか | sometime / someday |
Common mistakes
- Reordering the sentence to ask a question. Japanese doesn't flip the word order like English. Just add か to the end: 行きますか (✓), not a rearranged sentence.
- Forgetting か in polite questions. In です/ます speech the か is expected. これはペンです on its own is a statement; you need ですか to ask.
- Mixing up か and や for "or." か gives a real choice (コーヒーかお茶 = "coffee or tea"). や lists examples and is not a choice.
- Dropping the question word's particle confusion. なにか already means "something"; don't add を after it as if it were a normal object — なにか食べる, not なにを食べるか when you mean "eat something."
Quick recap
- Sentence + か = a question. Word order stays the same.
- A か B (nouns) = "A or B."
- Question word + か = indefinite: だれか (someone), なにか (something), どこか (somewhere), いつか (sometime).
- Casual speech often drops か and uses rising intonation instead.
Your turn
Choose the correct use of か — question, 'or', or indefinite.
Start the 5-question drill →Frequently asked questions
How do I make a question in Japanese?
Add か to the end of a plain statement. The word order doesn't change: ヤッタンは学生です ('Yattan is a student') becomes ヤッタンは学生ですか ('Is Yattan a student?').
Can I leave off か?
In casual speech, yes — Japanese often drops か and just uses rising intonation: 行く？ ('Are you going?'). In polite です/ます speech, keep the か.
What's the difference between か and や for 'or'?
か gives a genuine choice between nouns: コーヒーかお茶 ('coffee or tea'). や instead lists examples ('things like A and B') and is not a choice.
What does だれか mean?
A question word plus か becomes indefinite. だれか = 'someone', なにか = 'something', どこか = 'somewhere', いつか = 'sometime/someday'.