Korean numerals


The Korean language has two regularly used sets of numerals, a native Korean system and Sino-Korean system.

Construction

For both native and Sino- Korean numerals, the teens are represented by a combination of tens and the ones places. For instance, 15 would be sib-o, but not usually il-sib-o in the Sino-Korean system, and yeol-daseot in native Korean. Twenty through ninety are likewise represented in this place-holding manner in the Sino-Korean system, while Native Korean has its own unique set of words, as can be seen in the chart below. The grouping of large numbers in Korean follow the Chinese tradition of myriads rather than thousands. The Sino-Korean system is nearly entirely based on the Chinese numerals.
The distinction between the two numeral systems is very important. Everything that can be counted will use one of the two systems, but seldom both. Sino-Korean words are sometimes used to mark ordinal usage: yeol beon means "ten times" while sip beon means "number ten."
When denoting the age of a person, one will usually use sal for the native Korean numerals, and se for Sino-Korean. For example, seumul-daseot sal and i-sib-o se both mean 'twenty-five-year-old'. See also East Asian age reckoning.
The Sino-Korean numerals are used to denote the minute of time. For example, sam-sib-o bun means "__:35" or "thirty-five minutes."
The native Korean numerals are used for the hours in the 12-hour system and for the hours 0:00 to 12:00 in the 24-hour system. The hours 13:00 to 24:00 in the 24-hour system are denoted using both the native Korean numerals and the Sino-Korean numerals. For example, se si means '03:00' or '3:00 a.m./p.m.' and sip-chil si or yeol-ilgop si means '17:00'.
For counting above 100, Sino-Korean words are used, sometimes in combination: 101 can be baek-hana or baeg-il.
Some of the native numbers take a different form in front of measure words:
The descriptive forms for 1, 2, 3, 4, and 20 are formed by "dropping the last letter" from the original native cardinal, so to speak. Examples:
Something similar also occurs in some Sino-Korean cardinals:
The cardinals for three and four have alternative forms in front of some measure words:
As for counting days in native Korean, another set of unique words are used:
The native Korean saheul is often misunderstood as the Sino-Korean sail due to similar sounds. The two words are different in origin and have different meanings.

Cardinal numerals

Pronunciation

The initial consonants of measure words and numbers following the native cardinals 여덟 and 열 become tensed consonants when possible. Thus for example:
Several numerals have long vowels, namely 둘, 셋 and 넷, but these become short when combined with other numerals / nouns.
The usual liaison and consonant-tensing rules apply, so for example, 예순여섯 yesun-yeoseot is pronounced like and 칠십 chil-sip is pronounced like chil-ssip.

Constant suffixes used in Sino-Korean ordinal numerals

Beon, ho, cha, and hoe are always used with Sino-Korean or Arabic ordinal numerals. For example, Yihoseon is Line Number Two in a metropolitan subway system. Samsipchilbeongukdo is highway number 37. They cannot be used interchangeably.
906호 is 'Apt #906' in a mailing address. 906 without ho is not used in spoken Korean to imply apartment number or office suite number. The special prefix je is usually used in combination with suffixes to designate a specific event in sequential things such as the Olympics.

Substitution for disambiguation

In commerce or the financial sector, some hanja for each Sino-Korean numbers are replaced by alternative ones to prevent ambiguity or retouching.
EnglishHangulRegular hanjaFinancial hanja
one일一壹
two이二貳
three삼三參
four사四肆
five오五伍
six육, 륙六陸
seven칠七柒
eight팔八捌
nine구九玖
ten십十拾
hundred백百佰
thousand천千仟, 阡

For verbally communicating number sequences such as phone numbers, ID numbers, etc., especially over the phone, native Korean numbers for 1 and 2 are sometimes substituted for the Sino-Korean numbers. For example, o-o-o hana-dul-hana-dul instead of o-o-o il-i-il-i for '555-1212', or sa-o-i-hana instead of sa-o-i-il for '4521', because of the potential confusion between the two similar-sounding Sino-Korean numbers.
For the same reason, military transmissions are known to use mixed native Korean and Sino-Korean numerals: 공 하나 둘 삼 넷 오 여섯 칠 팔 아홉.