Counters (助数詞)

You’ll be able to

Explain why Japanese uses counters to count nouns
Choose the right counter for people, flat things, long things, and small animals
Handle the sound changes that occur with certain counter combinations

You cannot count nouns bare

Like Chinese, Japanese does not attach a number directly to most nouns; you need a counter (助数詞, josūshi) that matches the kind of thing being counted. The number and counter form a unit that typically follows the noun with a particle in between, or stands after it: リンゴを三つ買います (Ringo o mittsu kaimasu, “I buy three apples”). Different categories take different counters — people, flat objects, long objects, machines, small animals, and more each have their own.

Common counters

High-frequency counters: 〜人 (-nin) for people — 三人 (san-nin, “three people”), with irregulars 一人 (hitori, “one person”) and 二人 (futari, “two people”). 〜枚 (-mai) for flat, thin things (paper, tickets, shirts) — 二枚 (ni-mai). 〜本 (-hon) for long, cylindrical things (pens, bottles, umbrellas) — 三本 (san-bon). 〜匹 (-hiki) for small animals — 一匹 (ippiki). 〜台 (-dai) for machines/vehicles — 一台 (ichi-dai). 〜つ (-tsu) is a native general counter for objects up to ten — 一つ (hitotsu), 二つ (futatsu).

Sound changes with counters

Counters trigger euphonic sound changes depending on the number. With 〜本 (-hon): 一本 (ippon), 三本 (sanbon), 六本 (roppon), 八本 (happon) — the h shifts to p or b. With 〜匹 (-hiki): 一匹 (ippiki), 三匹 (sanbiki), 六匹 (roppiki). With 〜個 (-ko) for small round things: 一個 (ikko), 六個 (rokko). These shifts follow patterns tied to 1, 3, 6, 8, 10, so it is worth drilling the full 1–10 series for each common counter rather than assuming a regular reading.

Worked example

Say “There are two people and three dogs in the park,” choosing the correct counters for people and for small animals.

1.People use 〜人 (-nin), but “two people” is the irregular 二人 (futari), not ni-nin.
2.Small animals use 〜匹 (-hiki); “three [animals]” triggers a sound change to 三匹 (san-biki).
3.Use います (imasu) for animate existence: 公園に … がいます (Kōen ni … ga imasu).
4.Assemble the count phrases with the noun: 二人 for people, 犬が三匹 for the dogs.

Answer: 公園に二人と犬が三匹います。(Kōen ni futari to inu ga san-biki imasu.) “There are two people and three dogs in the park.” Note the irregular 二人 (futari) for two people and the sound change 三匹 (san-biki, not san-hiki) for the animal counter.

Checkpoint

Which counter is correct for counting three pencils (long, thin objects)?

Watch out

Memorize the irregular people counts: 一人 (hitori, “one person”) and 二人 (futari, “two people”) do not follow the -nin pattern. From three onward it is regular: 三人 (san-nin), 四人 (yo-nin, note the reading), 五人 (go-nin). These come up in nearly every conversation about family, friends, or groups.

Checkpoint

Why does “one bottle” become 一本 pronounced ippon rather than ichi-hon?

On the exam

You will not be tested on every rare counter, but people (〜人), flat things (〜枚), long things (〜本), small animals (〜匹), and the general 〜つ are essential. Drill each counter’s 1–10 series aloud so the sound changes come automatically under time pressure.

Answer the 2 checkpoints as you read.