Japanese Numbers & Dates: The Irregular Readings That Trip Everyone Up
You learned 4 is ใใ โ so why is the 4th of the month ใใฃใ? Japanese dates and numbers hide a set of irregular readings that come up every single day. Here is the list to memorize once and never struggle with again.
Why Readings Go Irregular
Japanese has two sets of number readings: native Japanese (ใฒใจใค, ใตใใคโฆ) and Sino-Japanese (ใใก, ใซ, ใใโฆ). Dates and counters mix them, and the leftovers from the older native system survive in the most common words โ especially the days of the month.
This is why 1ๆฅ is ใคใใใก (a completely different word) and 20ๆฅ is ใฏใคใ. You cannot derive these; you memorize them. The reward is that they are extremely high-frequency, so the effort pays back immediately.
Days of the Month (the irregular ones)
Days 1โ10 plus 14, 20, and 24 are irregular. From 11 onward (except 14/20/24) they are regular: ใใซใก.
Note: 24ๆฅ is ใซใใ ใใใฃใ (it reuses the ใใฃใ from 4ๆฅ).
4, 7, 9 โ the Numbers With Two Readings
4ๆฅ ใใฃใ, 4ไบบ ใใซใ, 4ๆ ใใ
7ๆฅ ใชใฎใ, 7ๆ ใใกใ
9ๆฅ ใใใฎใ, 9ๆ ใใ
Why it matters for listening: 7ๆ (ใใกใ) and 1ๆ (ใใกใ) sound dangerously similar at speed.
Counting People
The counter for people is ใไบบ (ใซใ), but the first two are irregular: ไธไบบ ใฒใจใ (one person), ไบไบบ ใตใใ (two people). From three onward it is regular: ไธไบบ ใใใซใ, ๅไบบ ใใซใ, ไบไบบ ใใซใ.
Teacherโs Note
Donโt learn these as a chart you stare at โ learn them by using your own calendar. Say todayโs date out loud every morning. After two weeks, ใคใใใก and ใฏใคใ will feel automatic, and youโll have covered the highest-frequency irregular readings in the language.
Japanese Numbers Guide โ
Counting & counters
Telling Time & Days โ
Time, days, weeks
Japanese Counters โ
Counter words & readings
Make the irregulars automatic
Nihongo Pass drills dates, times, and counters with spaced repetition and native audio โ so ใใฃใ and ใฏใคใ come without thinking.