Before you learn a single counter, there is one fact about Japanese numbers that reorganizes everything else: Japanese has two complete sets of number words for small quantities. One set — いち, に, さん — was borrowed from Chinese over a thousand years ago and is called Sino-Japanese (音読み, on'yomi). The other — ひとつ, ふたつ, みっつ — is the original native Japanese set (和語, wago). They are not regional variants or formal/casual pairs; they are two parallel systems, and Japanese uses both, every day, for different jobs. Sorting out which system a situation calls for is the real work of learning to count. The good news, saved for the end of this page, is that the workload is far smaller than "two whole number systems" makes it sound.
The two sets, one through ten
| Value | Sino (音読み) | Native (和語) |
|---|---|---|
| 1 | いち (ichi) | ひとつ (hitotsu) |
| 2 | に (ni) | ふたつ (futatsu) |
| 3 | さん (san) | みっつ (mittsu) |
| 4 | し / よん (shi / yon) | よっつ (yottsu) |
| 5 | ご (go) | いつつ (itsutsu) |
| 6 | ろく (roku) | むっつ (muttsu) |
| 7 | しち / なな (shichi / nana) | ななつ (nanatsu) |
| 8 | はち (hachi) | やっつ (yattsu) |
| 9 | きゅう / く (kyū / ku) | ここのつ (kokonotsu) |
| 10 | じゅう (jū) | とお (tō) |
Two things jump out. First, the native set is what you get by adding the generic counter つ to a native root (ひと + つ, ふた + つ…) — except とお (10), which has no つ. Second, the native set stops at ten. There is no native word for eleven; from 11 up, Japanese uses the Sino set exclusively.
コーヒーを二つください。
kōhī o futatsu kudasai
Two coffees, please.
りんごはいくつありますか。― 五つあります。
ringo wa ikutsu arimasu ka. — itsutsu arimasu
How many apples are there? — There are five.
When each system appears
The division of labor is not random. Here is the practical split:
Sino-Japanese (いち, に, さん…) is the default. Use it for:
- Any number above ten — the native set simply runs out.
- Most counters — 三人（さんにん, three people）, 五枚（ごまい, five sheets）, 十階（じゅっかい, tenth floor）. The Sino numeral fuses with the counter.
- Prices and money — 千二百円（せんにひゃくえん, 1,200 yen）.
- Phone numbers, room numbers, digits read one by one — read digit-by-digit in Sino.
- Math, dates, times, measurements — the whole quantitative world.
お会計は千二百円です。
o-kaikei wa sen-nihyaku-en desu
The bill is 1,200 yen.
電話番号は、090-1234-5678です。
denwa bangō wa, zero-kyū-zero no ichi-ni-san-yon no go-roku-nana-hachi desu
My phone number is 090-1234-5678.
子どもが三人います。
kodomo ga san-nin imasu
I have three children.
Native Japanese (ひとつ, ふたつ…) survives in a much smaller space. Use it for:
- The generic counter つ — counting concrete objects up to ten when you don't know (or don't need) a specific counter: 三つのケーキ, パンを二つ. See 〜つ: the generic counter.
- Ordering at a restaurant / shop — ビールを二つ, これを三つ.
- A short list of fossilized words — see the next section.
ビールを二つとコーラを一つお願いします。
bīru o futatsu to kōra o hitotsu onegai shimasu
Two beers and one cola, please.
ケーキを九つも食べたの？
kēki o kokonotsu mo tabeta no?
You ate as many as nine pieces of cake?!
The native survivors you must know
Beyond the つ counter, the native numerals cling on inside a handful of high-frequency words where the Sino reading would sound wrong or mean something else. These are memorized as vocabulary, not generated:
| Word | Reading | Meaning | Note |
|---|---|---|---|
| 一人 | ひとり (hitori) | one person / alone | not ×いちにん |
| 二人 | ふたり (futari) | two people | not ×ににん |
| 二十歳 | はたち (hatachi) | twenty years old | fully irregular |
| 一日 | ついたち (tsuitachi) | the 1st of the month | vs 一日（いちにち, one day） |
| 二十日 | はつか (hatsuka) | the 20th of the month | native-based |
一人で旅行するのが好きです。
hitori de ryokō suru no ga suki desu
I like traveling alone.
娘は来月二十歳になります。
musume wa raigetsu hatachi ni narimasu
My daughter turns twenty next month.
会議は八月一日です。
kaigi wa hachi-gatsu tsuitachi desu
The meeting is on August 1st.
The reassuring truth: the real workload is small
"Two entire number systems" sounds like double the memorization. It isn't. Because the native set dies at ten and survives mainly inside the つ counter plus that short list of fossils, what you actually need is:
- The full Sino set — いち through じゅう and beyond — which does the vast majority of the work (all large numbers, most counters, money, dates, times).
- The native numerals ひとつ〜とお — ten words — for the generic つ counter and casual "how many" answers.
- A handful of irregular words — ひとり, ふたり, はたち, ついたち — as vocabulary.
That's it. You are not learning two systems in parallel forever; you are learning one dominant system (Sino) plus a small, mostly self-contained pocket of native numerals.
Common mistakes
❌ ひとつ人が来ました。
Incorrect — the native つ-numeral cannot count people; use the 人 counter.
✅ 一人（ひとり）来ました。
hitori kimashita
One person came.
❌ りんごを二（に）ください。
Incorrect — a bare Sino numeral can't stand alone as 'two apples'; it needs a counter or the native form.
✅ りんごを二つ（ふたつ）ください。
ringo o futatsu kudasai
Two apples, please.
❌ じゅういちつ、じゅうにつ…（11以上をつで数える）
Incorrect — the native つ series stops at とお (10); it has no forms above ten.
✅ 十一個（じゅういっこ）、十二個（じゅうにこ）…
jūikko, jūniko…
From eleven up, switch to Sino + a counter.
❌ 電話番号をひとつ、ふたつ…と読む
Incorrect — phone numbers are read in the Sino set, digit by digit.
✅ 電話番号は「いち・に・さん…」と読む
denwa bangō wa 'ichi, ni, san…' to yomu
Read phone numbers in Sino numerals.
The mistake to watch for above all is reaching for a bare Sino numeral (に, さん) to count objects with no counter — that slot belongs to the native つ-forms — and, conversely, trying to push the native forms past ten or onto people, where Sino + a counter takes over.
Key takeaways
- Japanese has two small-number systems: Sino (いち・に・さん, borrowed) and native (ひとつ・ふたつ, original).
- Sino is the default: large numbers, most counters, money, phone numbers, dates, times.
- Native survives in the つ counter (1–10) and a few fossils: ひとり, ふたり, はたち, ついたち.
- You really only need ひとつ〜とお plus the full Sino set — the native system does not extend past ten.
Now practice Japanese
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Start learning Japanese→Related Topics
- Sino Numbers 1–10N5 — The Sino-Japanese numerals 一〜十 (ichi, ni, san…), and the crucial fact that 四, 七, and 九 each have two readings whose choice is fixed by the word or counter that follows.
- Native Numbers: ひとつ〜とおN5 — The native Japanese counting series ひとつ〜とお, used with the generic 〜つ counter as an all-purpose fallback for counting objects up to ten.
- Counters (助数詞): Why Japanese Counts with ClassifiersN5 — Why Japanese can't attach a bare number to a noun — every countable thing needs a counter (助数詞) chosen by its shape or category, exactly like English 'two sheets of paper' but obligatory for everything.