何 + [counter]
なん in front of a counter asks "how many". The answer swaps なん for a number and keeps the counter.
Like a number, the question word usually comes after the noun and its particle, straight in front of the verb, with no particle of its own.
| Counter | Question | Reading | Counts |
|---|---|---|---|
| 人 | 何人 | なんにん | people |
| 歳 | 何歳 | なんさい | years of age |
| 個 | 何個 | なんこ | small objects |
| 枚 | 何枚 | なんまい | flat things: paper, tickets, shirts |
| 冊 | 何冊 | なんさつ | books, notebooks |
| 台 | 何台 | なんだい | machines, vehicles |
| 本 | 何本 | なんぼん | long thin things: pens, bottles, trees |
| 匹 | 何匹 | なんびき | small animals |
| 杯 | 何杯 | なんばい | cups and glasses of something |
| 回 | 何回 | なんかい | times |
| 分 | 何分 | なんぷん | minutes |
| 階 | 何階 | なんがい | floors of a building |
Five of these change their first sound after なん: 本 is ほん but 何本 is なんぼん, 匹 is ひき but 何匹 is なんびき, 杯 is はい but 何杯 is なんばい, 分 is ふん but 何分 is なんぷん, and 階 is かい but 何階 is なんがい.
The つ counter has its own question word, いくつ. ×なんつ is wrong.
A price is asked with いくら.
With the counters for clock time and dates, the question asks which one: 何時 (なんじ) is "what time", 何月 (なんがつ) "what month", 何曜日 (なんようび) "what day of the week". 何階 asks which floor in the same way.
何日 (なんにち) and 何年 (なんねん) work both ways: "what date" or "how many days", "what year" or "how many years". A length of time in hours is 何時間 (なんじかん).
These go beyond asking how many.
Before a counter, 何 is read なん. Read なに in front of a noun, it asks "what …" instead, and the two can share a spelling: 何人 read なんにん is "how many people", and read なにじん it is "what nationality".