Japanese counters
You cannot say “three dogs” in Japanese without saying what kind of thing you are counting. That word is a counter, and the number in front of it changes shape depending on which one you pick — 一本 is いっぽん but 一枚 is いちまい. Here are the 26 you actually need, each with all ten readings.
The sound changes, in one table
Three quarters of the difficulty of counters is not remembering which one to use — it is the sound changes. Luckily they follow the initial consonant of the counter, so learning one counter teaches you a whole family.
| Family | What happens | Example (本) |
|---|---|---|
| は-row (本・匹・杯・分・泊) | 1・6・8・10 take small っ and は→ぱ; 3 takes ん and は→ば | いっぽん・さんぼん・ろっぽん |
| か-row (回・階・個・ヶ月) | 1・6・8・10 take small っ | いっかい・ろっかい・じゅっかい |
| さ-row (冊・歳・足) | 1・8・10 take small っ | いっさつ・はっさつ・じゅっさつ |
| た-row (頭・通・着) | 1・8・10 take small っ | いっとう・はっとう・じゅっとう |
| everything else (枚・台・人・名) | nothing changes | いちまい・にまい・さんまい |
じゅっ- is also said じっ- in careful speech (十分 = じゅっぷん or じっぷん). Both are correct; じゅっ- is what you will hear most.
Which counter do I use?
When you genuinely do not know, つ (up to ten) or 個 is almost always understood. Native speakers hesitate over rare counters too.
Numbers themselves are on the Japanese numbers page, and the kanji for each counter link through to their own study pages.