Korean Numbers: Dates and Phone Numbers (Sino-Korean)

Dates and phone numbers always use Sino-Korean. Months: 일월(Jan), 이월(Feb)... 십이월(Dec). Days: 일일(1st), 이일(2nd)... Phone numbers are read digit by digit.

The Rule

Dates and phone numbers always use Sino-Korean. Months: 일월(Jan), 이월(Feb)... 십이월(Dec). Days: 일일(1st), 이일(2nd)... Phone numbers are read digit by digit. Korean has TWO completely separate number systems — Native Korean (하나, 둘, 셋) and Sino-Korean (일, 이, 삼). English speakers must learn WHEN to use which system, because mixing them up is a common and noticeable mistake.

Why English Speakers Get It Wrong

English has one number system. Korean has two, and you must pick the RIGHT one depending on what you're counting. Using Sino-Korean where Native Korean is required (or vice versa) sounds as wrong to Koreans as saying "I have three-th cats" sounds in English. Key numbers for this topic: • 월 (wol) = month • 일 (il) = day

How It Works

Dates and phone numbers always use Sino-Korean. Months: 일월(Jan), 이월(Feb)... 십이월(Dec). Days: 일일(1st), 이일(2nd)... Phone numbers are read digit by digit. Examples: • 삼월 이십일 (samwor isipir) — "March 20th" • 공일공-사이사이-육칠팔구 (gongirgong-saisai-yukchirpargu) — "010-4545-6789" For phone numbers, 0 is read as 공 (gong), not 영 (yeong). All Korean mobile numbers start with 010. Dates use Sino-Korean exclusively — never native Korean numbers for months or days.

Real Examples

• 삼월 이십일 (samwor isipir) — "March 20th" • 공일공-사이사이-육칠팔구 (gongirgong-saisai-yukchirpargu) — "010-4545-6789"

Common Mistakes

❌ Using the wrong number system for the context ✅ Dates and Phone Numbers (Sino-Korean) uses Sino-Korean numbers → Each context has a fixed number system. Memorize which system goes with which context. ❌ Forgetting the shortened forms (하나→한, 둘→두, etc.) ✅ Native Korean numbers 1-4 change form before counters → This is mandatory, not optional. 하나 개 is wrong; 한 개 is correct.

Quick Tip

For phone numbers, 0 is read as 공 (gong), not 영 (yeong). All Korean mobile numbers start with 010. Dates use Sino-Korean exclusively — never native Korean numbers for months or days. Practice tip: Pick one number context (like ordering food or telling time) and drill it until it's automatic. Don't try to learn both systems at once — master one usage scenario at a time.

For phone numbers, 0 is read as 공 (gong), not 영 (yeong). All Korean mobile numbers start with 010. Dates use Sino-Korean exclusively — never native Korean numbers for months or days.

Examples

삼월 이십일 — samwor isipir — March 20th

공일공-사이사이-육칠팔구 — gongirgong-saisai-yukchirpargu — 010-4545-6789