Japanese Numbers & Counter Words
From a JLPT N1 certified teacher. Japanese has two number systems and a unique counter word system that changes how you count everything from people to flat objects. This guide makes it all clear.
Why Japanese Numbers Need Special Attention
Japanese has two complete number systems: the native Japanese system (ใฒใจใค, ใตใใค, ใฟใฃใค...) used for counting general objects 1 through 10, and the Sino-Japanese system (ใใก, ใซ, ใใ...) borrowed from Chinese, used for everything else including large numbers, math, dates, and ages.
On top of this, Japanese uses counter words (ๅฉๆฐ่ฉ โ josushi) โ special suffixes attached to numbers that change depending on what you are counting. People use ไบบ, flat objects use ๆ, long objects use ๆฌ, small animals use ๅน, and so on. There are over 500 counters, but about 20 cover daily life.
The JLPT N5 exam tests basic numbers, the native counting system, and approximately 10 common counters. Getting these right is essential because numbers appear in every section of the exam โ listening (prices, times, dates), reading (schedules, quantities), and vocabulary (counter word selection).
The Sino-Japanese Number System (ใใก, ใซ, ใใ...)
The Sino-Japanese numbers are the workhorse of the Japanese counting system. ใใก (1), ใซ (2), ใใ (3), ใ/ใใ (4), ใ (5), ใใ (6), ใใก/ใชใช (7), ใฏใก (8), ใใ ใ/ใ (9), ใใ ใ (10). These combine logically: 11 = ใใ ใใใก, 20 = ใซใใ ใ, 35 = ใใใใ ใใ.
For larger numbers: ็พ (ใฒใใ, 100), ๅ (ใใ, 1,000), ไธ (ใพใ, 10,000). Note that Japanese groups numbers in units of 10,000 (ไธ), not 1,000 like English. So 100,000 is ๅไธ (10 man) and 1,000,000 is ็พไธ (100 man). This grouping difference causes confusion for English speakers working with large numbers.
The numbers 4, 7, and 9 each have two readings. ใ/ใใ (4), ใใก/ใชใช (7), ใ/ใใ ใ (9). The alternate readings exist because ใ sounds like ๆญป (death), ใ sounds like ่ฆ (suffering), and ใใก is easily confused with ใใก (1). In most daily contexts, ใใ, ใชใช, and ใใ ใ are preferred.
- โขAlways use ใใ (4), ใชใช (7), and ใใ ใ (9) when counting unless a specific counter requires ใ, ใใก, or ใ.
- โขPractice building numbers aloud: 256 = ใซใฒใใใใใ ใใใ. Speed comes from drilling combinations.
- Sound changes: 300 = ใใใณใใ (not ใใใฒใใ), 600 = ใใฃใดใใ, 800 = ใฏใฃใดใใ. These are tested on JLPT.
- 10,000 grouping trap: when hearing prices in Japanese, mentally convert ไธ units. 3ไธ5ๅ = 35,000, not 35 million.
The Native Japanese System (ใฒใจใค, ใตใใค, ใฟใฃใค...)
The native Japanese counting system only goes from 1 to 10: ใฒใจใค (1), ใตใใค (2), ใฟใฃใค (3), ใใฃใค (4), ใใคใค (5), ใใฃใค (6), ใชใชใค (7), ใใฃใค (8), ใใใฎใค (9), ใจใ (10). Above 10, only the Sino-Japanese system is used.
This system is used when counting general objects without a specific counter โ ordering food (ใตใใคใใ ใใ โ 'two, please'), counting abstract things, or when you do not know the correct counter. It is the universal fallback that always works for quantities 1-10.
Children's ages 1-9 also use a variant of this system: ใฒใจใค, ใตใใค... are commonly used for young children's ages (3ๆญณ can be said as ใฟใฃใค in casual speech). For ages 10 and above, the Sino-Japanese system with ๆญณ (ใใ) is standard.
- โขMemorize ใฒใจใค through ใจใ as a rhythmic chant โ the pattern of ใค endings makes them easier to remember as a set.
- โขWhen ordering at a restaurant and you forget the counter, use this system: ใฟใฃใคใใ ใใ (three, please) always works.
- Common mistake: saying ใใ ใใใฃใค for 11. The native system stops at 10. For 11+, use Sino-Japanese numbers with the appropriate counter.
- โขThe native numbers appear frequently in JLPT N5 listening โ practice hearing the difference between ใตใใค (2) and ใฟใฃใค (3).
Essential Counter Words for JLPT N5
Counter words are attached after the number to specify what you are counting. The essential N5 counters: ไบบ (ใซใ โ people, but note: ใฒใจใ for 1 person, ใตใใ for 2), ๅ (ใ โ small objects), ๆ (ใพใ โ flat things: paper, tickets, shirts), ๆฌ (ใปใ โ long things: pencils, bottles, roads), ๅน (ใฒใ โ small animals), ๅฐ (ใ ใ โ machines/vehicles), ๅ (ใใค โ books), ๆฏ (ใฏใ โ cups/glasses).
Sound changes (้ฃๆฟ) make counters tricky. ๆฌ: ใใฃใฝใ, ใซใปใ, ใใใผใ (not ใใกใปใ, ใซใปใ, ใใใปใ). ๅน: ใใฃใดใ, ใซใฒใ, ใใใณใ. ๆฏ: ใใฃใฑใ, ใซใฏใ, ใใใฐใ. These irregular readings must be memorized โ they follow patterns but the patterns have exceptions.
The most important counter for daily life is ๅ (ใ). It works for almost any small-to-medium object and is increasingly used as a general-purpose counter in casual speech, similar to how the native counting system (ใฒใจใค, ใตใใค) functions as a fallback.
- โขMemorize ใฒใจใ and ใตใใ first โ these irregular people-counters appear in almost every JLPT listening section.
- โขLearn counter sound changes in groups of 3: 1, 3, and 6/8 are where most changes happen (ใใฃใฝใ, ใใใผใ, ใใฃใฝใ, ใฏใฃใฝใ).
- ใซใปใ (2 long things) and ใซใปใ (Japan) are written and read the same. Context makes the meaning clear.
- ๅไบบ is ใใซใ (not ใใซใ, which sounds like ๆญปไบบ โ dead person). Always use ใ for 4 with ไบบ.
Dates, Months & Days of the Week
Months are straightforward: number + ๆ (ใใค). January = ไธๆ (ใใกใใค), February = ไบๆ (ใซใใค), through December = ๅไบๆ (ใใ ใใซใใค). No exceptions, no irregular readings.
Days of the month, however, are highly irregular for the first 10 days and the 14th, 20th, and 24th. 1ๆฅ = ใคใใใก, 2ๆฅ = ใตใคใ, 3ๆฅ = ใฟใฃใ... These use the native Japanese number system with special readings. From 11ๆฅ onward, most follow the pattern: number + ใซใก (ใใ ใใใกใซใก, etc.).
Days of the week follow a pattern based on celestial objects: ๆๆๆฅ (Monday/Moon), ็ซๆๆฅ (Tuesday/Fire), ๆฐดๆๆฅ (Wednesday/Water), ๆจๆๆฅ (Thursday/Wood), ้ๆๆฅ (Friday/Gold), ๅๆๆฅ (Saturday/Earth), ๆฅๆๆฅ (Sunday/Sun). Knowing the kanji for each day helps you remember them as a system.
- โขDrill 1ๆฅ through 10ๆฅ as a set โ these irregular day readings are a guaranteed JLPT N5 topic.
- โขDays of the week trick: Mon-Sun = ๆ็ซๆฐดๆจ้ๅๆฅ. The kanji appear in this order, and each maps to a natural element.
- 4ๆ = ใใใค (not ใใใใค), 7ๆ = ใใกใใค (not ใชใชใใค), 9ๆ = ใใใค (not ใใ ใใใค). Months use the older readings for 4, 7, 9.
- 8ๆฅ = ใใใ (not ใฏใกใซใก). 20ๆฅ = ใฏใคใ (not ใซใใ ใใซใก). These exceptions are tested on JLPT every year.
Numbers in Real Life & JLPT
In daily Japanese life, numbers appear constantly: prices (ใใใณใใใใ โ 300 yen), phone numbers (digit by digit), addresses (district numbers + building numbers), ages (number + ๆญณ), and time expressions (number + ๆ/ๅ). Being comfortable with number listening is essential.
The JLPT tests numbers primarily through listening. You will hear: store prices and making change, appointment times and scheduling, quantities being ordered, and phone numbers or addresses. The key skill is rapid recognition โ you do not have time to mentally convert, so practice hearing numbers at natural speed.
A practical study method: practice with real Japanese prices. Look up restaurant menus, convenience store prices, or train fares online. Read the prices aloud in Japanese. This builds the number-reading automaticity that the JLPT requires.
- โขPractice listening to prices at natural speed โ Japanese cashiers speak quickly. Train with audio at 1.0x speed, not slowed down.
- โขPhone numbers are read digit by digit: 090-1234-5678 = ใผใญใใ ใใผใญ ใฎ ใใกใซใใใใ ใฎ ใใใใชใชใฏใก.
- Japanese uses 0 (ใผใญ or ใใ). ใผใญ is more common in daily speech; ใใ is used in formal contexts and weather reports.
- โขFor JLPT listening: when you hear a price, write the number immediately โ do not wait to hear the whole sentence.
Teacher Notes by Language Background
Vietnamese also has counter words (classifiers) like con (animals), cai (general objects), and quyen (books), so the concept of Japanese counters will feel natural. The key difference is that Japanese counter sound changes (rendaku) are more complex. Vietnamese speakers often find the native Japanese number system (hitotsu, futatsu) unusual since Vietnamese does not have a parallel system.
Indonesian does not use counter words as extensively, so the Japanese counter system will be new. Start with ko (general objects) as your fallback counter โ it works similarly to Indonesian buah. The 10,000-unit grouping may cause confusion since Indonesian uses the same 1,000 grouping as English. Practice converting between the two systems early.
Mongolian number structure is similar to Japanese in some ways (10+3 = 13), which helps with basic number building. However, Japanese counter words have no Mongolian equivalent. Focus on learning counters through daily use situations (ordering food, buying tickets) rather than memorizing lists. The irregular day-of-month readings (tsuitachi, futsuka, etc.) require dedicated drill time.
Frequently Asked Questions
Why does Japanese have two number systems?+
How many counter words do I need for JLPT N5?+
What happens if I use the wrong counter?+
Why do numbers 4, 7, and 9 have two readings?+
How do I learn the irregular day-of-month readings?+
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