The Korean language has two regularly used sets of numerals: a native Korean system and Sino-Korean system. The native Korean number system is used for general counting, like counting up to 99. It is also used to count people, hours, objects, ages, and more. Sino-Korean numbers on the other hand are used for purposes such as dates, money, minutes, addresses, phone numbers, and numbers above 99.
For both native and Sino-Korean numerals, the teens (11 through 19) 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 follows the Chinese tradition of myriads (10000) rather than thousands (1000). 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'.
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:
Korean has several words formed with two or three consecutive numbers. Some of them have irregular or alternative forms.
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.
In numbers above 10, elements are combined from largest to smallest, and zeros are implied. Hanja and Hangul numerals are both multiplicative additive rather than positional; for example, the number 20 is written as the character for two (äºÂ/ì´) followed by the character for ten (Ã¥ÂÂ/ìÂÂ), resulting in two tens, or twenty (äºÂÃ¥ÂÂ/ì´ìÂÂ).
The initial consonants of measure words and numbers following the native cardinals ('eight', only when the is not pronounced) and ('ten') become tensed consonants when possible. Thus for example:
Several numerals have long vowels, namely (two), (three) and (four), but these become short when combined with other numerals / nouns (such as in twelve, thirteen, fourteen and so on).
The usual liaison and consonant-tensing rules apply, so for example, yesun-yeoseot (sixty-six) is pronounced like (yesun-nyeoseot) and chil-sip (seventy) is pronounced like chil-ssip.
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.
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.
In commerce or the financial sector, some Hanja for each Sino-Korean numbers are replaced by alternative ones to prevent ambiguity or retouching.
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 <span style="color:blue">native Korean</span> and <span style="color:red">Sino-Korean</span> numerals: