Hangul
The same hangul letters are used to write the language in the North and the South. However, in the North, the stroke that distinguishes ㅌ |tʰ| from ㄷ |t| is written above rather than inside the letter as in the South.
In the South, the vowel digraphs and trigraphs ㅐ |ɛ|, ㅒ |jɛ|, ㅔ |e|, ㅖ |je|, ㅘ |wa|, ㅙ |wɛ|, ㅚ |ø|, ㅝ |wʌ|, ㅞ |we|, ㅟ |y|, ㅢ |ɰi| and the consonant digraphs ㄲ |k͈|, ㄸ |t͈|, ㅃ |p͈|, ㅆ |s͈|, ㅉ |tɕ͈| are not treated as separate letters, whereas in the North they are. Some letters and digraphs have different names in the North and in the South.
| Letter | North Korean name | South Korean name |
|---|---|---|
| ㄱ |k| | 기윽 | 기역 |
| ㄷ |t| | 디읃 | 디귿 |
| ㅅ |s| | 시읏 | 시옷 |
| ㄲ |k͈| | 된기윽 | 쌍기역 |
| ㄸ |t͈| | 된디읃 | 쌍디귿 |
| ㅃ |p͈| | 된비읍 | 쌍비읍 |
| ㅆ |s͈| | 된시읏 | 쌍시옷 |
| ㅉ |tɕ͈| | 된지읒 | 쌍지읒 |
The names used in the South are the ones found in Hunmongjahoe (훈몽자회, 訓蒙字會, published 1527). The names used in the North are formed mechanically with the pattern "letter + 이 + 으 + letter". Also for the tensed consonants, in the South, they are called "double" (쌍- /s͈aŋ-/) consonants, while in the North, they are called "strong" (된- /tøːn-/) consonants.
Read more about this topic: Languages Of North Korea