Korean Numbers: Complete Guide to Native and Sino-Korean Systems

Why Does Korean Have Two Number Systems?

One of the most surprising things about Korean for new learners is that it has not one, but two complete number systems. Native Korean numbers (고유어 수사) are the original Korean counting words, while Sino-Korean numbers (한자어 수사) were borrowed from Chinese characters centuries ago. Both systems are used daily by every Korean speaker, and knowing when to use which is essential for sounding natural.

Think of it like English using both "first, second, third" (ordinal) and "one, two, three" (cardinal) -- except in Korean, the distinction runs much deeper and applies to different real-world situations.

Native Korean Numbers (하나, 둘, 셋)

Native Korean numbers are used for counting items (with counter words), telling your age, and for hours when telling time. These numbers only go up to 99 in everyday use. Above that, Koreans switch to Sino-Korean numbers.

For numbers above 10, combine the tens and ones: 11 = 열하나 (yeol-hana), 20 = 스물 (seumul), 25 = 스물다섯 (seumul-daseot), 30 = 서른 (seoreun), 40 = 마흔 (maheun), 50 = 쉰 (swin).

Sino-Korean Numbers (일, 이, 삼)

Sino-Korean numbers are derived from Chinese characters and are used for dates, money, phone numbers, addresses, minutes and seconds, and numbers above 100. This system is more regular and easier to learn since it follows a simple pattern.

Larger Sino-Korean numbers follow a predictable pattern: 11 = 십일 (sib-il, literally "ten-one"), 20 = 이십 (i-sip, "two-ten"), 100 = 백 (baek), 1,000 = 천 (cheon), 10,000 = 만 (man). For example, 2,500 = 이천오백 (i-cheon-o-baek).

When to Use Which System

This is where most learners struggle. Here is a clear breakdown of when each system applies in daily Korean life.

Essential Counter Words (단위 명사)

Korean uses counter words (also called classifiers) between the number and the noun, similar to how English says "two sheets of paper" instead of "two papers." Counter words are always paired with native Korean numbers. Here are the most common ones you need to know.

Counting Age in Korean

Age in Korean uses native Korean numbers with the counter word 살 (sal). This is one of the most common uses of native numbers you will encounter. Note that Korea traditionally used a different age-counting system (Korean age), but since 2023, South Korea officially uses international age for legal and administrative purposes.

Money and Prices

Korean currency (원, won) always uses Sino-Korean numbers. Since the smallest coin commonly used is 100 won, you will deal with larger numbers frequently. A typical lunch might cost 8,000-12,000 won.

Telling Time: Both Systems Together

Telling time in Korean is the perfect example of why you need both number systems. The hours use native Korean numbers while the minutes use Sino-Korean numbers. This is one of the trickiest aspects for beginners, but with practice it becomes second nature.

Practice Makes Perfect

The best way to master Korean numbers is through daily practice. Try counting objects around you using native Korean numbers with the counter 개 (gae). Read prices in Korean when you see them. Practice telling the current time in Korean, remembering to switch systems between hours and minutes. With consistent practice, using the right number system will become automatic.

• Start with Sino-Korean 1-10 since the pattern is more regular
• Then learn native Korean 1-10 and their shortened forms
• Memorize the top 5 counter words: 개, 명, 잔, 마리, 권
• Practice telling time every hour to drill both systems together
• Use Sino-Korean numbers when reading prices, dates, and phone numbers
• Use native Korean numbers when counting things you can see around you