Ask what you are counting first

Korean has two commonly used number systems. That does not mean you must guess between two random words every time you see a digit. The thing being counted usually tells you which system to choose.

Sino-Korean numbers include 일, 이, 삼. They have roots in Chinese and are now ordinary Korean words. Native Korean numbers include 하나, 둘, 셋. You will meet both early, especially when ordering something or telling the time.

For this first lesson, concentrate on four jobs: read a price, recognise a numbered label, say a small quantity, and understand a clock. We are not covering every counter, large-number unit, date exception, or age convention. Keep this as a decision guide rather than trying to absorb all Korean number usage at once.

A small decision guide

Notice why the last two rows differ. “Two cups” tells you a quantity; “bus number 2” names a route. Learning a numeral together with the word after it is more useful than memorising two isolated lists.

Learn 1–10 in both systems

Read the Hangul while listening to recordings; some written consonants sound different when they meet another sound. If Hangul is new, begin with the reading guide, then learn the first five numbers of one system before mixing the two.

You will also see 영 and 공 for zero. 영 is common in numerical values; 공 is common when reading phone-number digits. These uses depend on context, so do not assume every zero is always said the same way.

Build a few larger numbers

In Sino-Korean, 십 is ten. Add a number after it for the ones: 십이 is 12, 십칠 is 17. Put the number of tens before it: 삼십 is 30. Combine both positions for 삼십육, 36. You do not need a word for “and.”

The same construction idea helps with native numbers from 11 to 19: 열하나 is 11 and 열여섯 is 16. The word for 20 is 스물; it is not a form made by translating “two tens.” Learn the native tens later as their own words.

For a first price, learn 백 (100), 천 (1,000), and 원 (won). 삼천 원 is 3,000 won; 오천오백 원 is 5,500 won. Those are practice prices, not promises about what a drink costs. Written prices often use digits, such as 5,500원, even when someone says the full Korean number aloud.

Why 하나 becomes 한 before a counter

A counter is a word that goes with a number to count a type of thing. 개 is a general item counter and 잔 counts cups or glasses. Before many counters, the first four native numbers shorten:

Twenty changes too: 스물 becomes 스무 directly before a counter, as in 스무 개. In 21, the final 하나 changes instead: 스물한 개. For now, practise 한, 두, 세, 네 with one familiar counter. Do not shorten a number just because it happens to appear anywhere in a sentence.

A clock uses both systems together

In 세 시 십오 분, the hour 세 comes from native 셋, while the minutes 십오 use Sino-Korean. The expression means 3:15. For 2:40, use 두 시 사십 분. Say the hour first, then the minutes, just as the clock displays them.

Keep the purpose visible during practice: write “price,” “cups,” or “clock” beside each example. If you only write the bare digit 3, both 삼 and 셋 can be correct in their own setting. The context is part of the answer.

Check the system before the number

Next, practise one real task: read three sample prices, then order two drinks using your first travel phrases. Keep the numeral and its counter together when you review.

A small listening check

Reference and further practice

The examples and practice tasks in this guide were written for Korean With a Local. For reference and further study:

• GO! Billy Korean: beginner counting sequence — A sequence that separates the number systems before counters.
• GO! Billy Korean: counters lesson (PDF) — Counter use, including money and people. External study material; not a worksheet from this site.

Reviewed September 3, 2026. Found a mistake? Send a correction.