Japanese Question Words (疑問詞): Complete Beginner Guide

What Are Japanese Question Words?

Question words — called 疑問詞 (gimonshi) in Japanese — are the building blocks of every real conversation. They let you ask what, who, where, when, why, and how. Here is the best news for beginners: Japanese question words do not move to the front of a sentence the way English question words do. They stay exactly where the answer would go. Once you know the word and its particle partner, you can drop it straight into sentences you already know.

Cultural note: In casual spoken Japanese, a rising intonation at the end of a sentence can turn any statement into a question, even without a question word. You will often hear Japanese speakers simply raise their voice at the end rather than adding the question particle か (ka). Question words, though, always make your intent unmistakable — which is exactly why they are so useful from day one.

All 10 Japanese Question Words at a Glance

Learn these ten words and you can ask almost anything. Every entry shows the kanji (where standard), kana reading, Hepburn romaji, and English meaning. Formal and polite variants are covered in their own section below.

A note on why: なぜ (naze) is the more formal or written form — it sounds precise, almost analytical. どうして (doushite) is warmer and far more common in everyday conversation. You will encounter both, so learn to recognise each.

Question Words in Real Sentences

This is where it clicks. Watch how each question word simply replaces the answer slot — the rest of the sentence stays the same. You will find these patterns combining naturally with time vocabulary from the time expressions lesson and with travel phrases from the travel words guide.

1. Asking "what"

これは何ですか？ Kore wa nan desu ka? What is this?

2. Asking "where"

トイレはどこですか？ Toire wa doko desu ka? Where is the bathroom?

3. Asking "who"

あの人は誰ですか？ Ano hito wa dare desu ka? Who is that person?

4. Asking "when"

パーティーはいつですか？ Paatii wa itsu desu ka? When is the party?

5. Asking "how much"

これはいくらですか？ Kore wa ikura desu ka? How much is this?

The basic pattern for most beginner questions is: topic は + question word + ですか. The particle that follows a question word shifts depending on the verb — for example, どこに (doko ni — where to) versus どこで (doko de — where at). You will explore those combinations in depth in the location words guide.

The なに vs なん Rule: Never Confuse Them Again

This is the single most common stumbling block at this level, so it deserves a full explanation rather than just a warning.

Both なに and なん are readings of the same kanji, 何, meaning what. The choice between them is phonetic — it depends entirely on the sound that follows.

Use なん (nan) before words starting with a d, t, or n sound, and before です / だ:

Use なに (nani) before particles を, が, か, and in most other positions:

In casual speech, native speakers blur this distinction occasionally — but in polite or formal Japanese it matters, and using なん correctly makes your Japanese sound noticeably more natural to a trained ear.

Formal and Polite Variants

Japanese adjusts for relationship and context, and question words are no exception. If you have been building your vocabulary with the family words lesson, you are already familiar with how Japanese shifts register. In formal or business situations, these polite question words are the expected forms.

Two things worth knowing right away:

1. どちら literally means "which direction" but functions as the polite substitute for both where and which one — context clarifies meaning.
2. いかが is used almost exclusively in polite invitations: お茶はいかがですか？ (Ocha wa ikaga desu ka?) — How about some tea? You would not use it to ask how someone performs a task.

Common Mistakes with Japanese Question Words

1. なに vs なん (the most frequent error) Learners often say nani desu ka instead of nan desu ka. The word desu starts with a d sound, so it needs なん. The error is understood, but it sounds unnatural — like saying "whatted" instead of "what." Fix it early and it will never bother you again.

2. Dropping the question particle か In casual conversation, か can be omitted if your intonation clearly rises. In polite speech (です/ます form), always include it: どこですか, not a flat-toned どこです. Without か and without a rising intonation, the sentence lands as a statement, not a question.

3. どれ in formal situations Learners often reach for どれ even in polite contexts. In a shop, a meeting, or any formal exchange, どちら is the expected form — even if there are three or more options. Using どれ in those settings can come across as blunt or casual in a way you did not intend.

4. Overusing なぜ in conversation なぜ sounds formal and can carry a slightly accusatory nuance, much like "For what reason...?" in English. In everyday conversation, どうして sounds warmer and more natural. Save なぜ for writing or formal speech.

5. Mixing いつ with compound adverbs いつ (itsu) is a standalone question word, but it also appears inside fixed phrases: いつも (always), いつか (someday), いつでも (whenever). These are adverbs, not questions. Learners sometimes muddle them when first encountering phrases like いつでもいいです ("anytime is fine").

Practice Quiz

Cover the Answer column with your hand and work through each section before checking.

① Romaji reading

② English meaning

③ Fill in the Japanese

④ なに or なん?

FAQ

What is the Japanese word for "what"?

The Japanese word for what is 何 (なに / nani). Before です、だ, or words starting with d, t, or n sounds it becomes なん (nan). For example: Kore wa nan desu ka? (これは何ですか？) means "What is this?" — nan, not nani, because desu follows.

How do you form a question in Japanese using a question word?

Japanese question words stay in the same position as the answer would occupy — they do not move to the front of the sentence as in English. A reliable beginner pattern is: topic は + question word + ですか. Example: Paatii wa itsu desu ka? (パーティーはいつですか？) — "When is the party?"

What is the difference between どれ and どちら?

どれ (dore) means "which one" from a group of three or more and is casual. どちら (dochira) is the polite equivalent and also means "which direction / where" in formal contexts. In shops, offices, or business settings, always use どちら — even when choosing from more than two items.

When should I use どうして instead of なぜ?

Use どうして (doushite) in everyday conversation — it sounds warm and natural. Use なぜ (naze) in formal speech, written Japanese, or when you want to sound precise and serious. In casual settings, なぜ can sound unexpectedly stern, similar to "For what reason...?" in formal English.

Continue Learning

Question words are the connective tissue of Japanese — they transform isolated vocabulary into real exchanges. Here is where to go from here:

• ← Review the time expressions that work with いつ and 何時 — the lesson immediately before this one
• → Build your describing power with useful Japanese adjectives — the next step after you can ask the question is knowing how to describe the answer

Want to practise asking and answering these exact question words in a real conversation? Start your Free Trial with a one-on-one Japanese tutor over LINE and get personalised feedback on your pronunciation and particle use from the very first session.

This article is Lesson 33 of the Kind Japanese 100-day beginner curriculum.