There are two ways of expressing a person’s age in Korean
1. Pure Korean Number 살
2. Sino-Korean Number 세
The first way is normally used in everyday conversation. The second is used
in more formal situations, such as for filling out forms:
(1) 수잔은 스무 살이에요.
Susan is twenty years old.
(2) 이름: 수잔 Name: Susan
나이: 20 세 Age: 20 years
(Note that Sino-Korean numbers are more often written as digits. 20 세
is pronounced [이십 세].)
[A/N: PREFER TO "LET'S COUNT (PART 1&2)" FOR KOREAN NUMBERS. BUT IT'S BETTER AND A MUST IF YOU ALREADY MEMORIZE THE TWO DIFFERENT KOREAN NUMBERS]
A modified form of 하나, 둘, 셋, 넷 and 스물 is used in conjunction with counting nouns such as 살: 한 살, 두 살, 세 살, 네 살, 스무
살. No other numbers are modified. Thus, you would say 다섯 살 or 여덟 살.