Writing

The top three commonly used is Romanized Poplar Alphabet, Pahawh Hmong and Koryi writing system.

Romanized Poplar Alphabet
The Romanized Popular Alphabet (RPA) or Hmong RPA (also Roman Popular Alphabet), is a system of romanization for the various dialects of the Hmong language. Created in Laos between 1951 and 1953 by a group of missionaries and Hmong advisers, it has gone on to become the most widespread system for writing the Hmong language in the West. It is also used in Southeast Asia and China alongside other writing systems, notably Pahawh Hmong.

Pahawh Hmong
Pahawh Hmong (RPA: Phajhauj Hmoob [pʰâ hâu m̥ɔ́ŋ], known also as Ntawv Pahawh, Ntawv Keeb, Ntawv Caub Fab, Ntawv Soob Lwj) is an indigenous semi-syllabic script used to write the Hmong language.

Kaulim
Kaulim Sau Daim (KSD: 고리) is the native alphabet of the Korean language, as distinguished from the logographic Sino-Korean hanja system. It was created in the mid-fifteenth century, and is now the official script of both North Korea and South Korea, being co-official in the Yanbian Korean Autonomous Prefecture of China.

Hangul is a phonemic alphabet organized into syllabic blocks. Each block consists of at least two of the 24 Hangul letters (jamo), with at least one each of the 14 consonants and 10 vowels. These syllabic blocks can be written horizontally from left to right as well as vertically from top to bottom in columns from right to left. Originally, the alphabet had several additional letters.

Alphabet

 * ㄱ ㄲ ㄴ ㄷ ㄸ ㄹ ㅁ ㅂ ㅃ ㅅ ㅆ ㅇ ㅈ ㅉ ㅊ ㅋ ㅌ ㅍ ㅎ
 * ㅏ ㅐ ㅑ ㅒ ㅓ ㅔ ㅕ ㅖ ㅗ ㅘ ㅙ ㅚ ㅛ ㅜ ㅝ ㅞ ㅟ ㅠ ㅡ ㅢ ㅣ

History
Durign the 15th Century, Txiameng travelled far to the Goryeo and learned the alphabet of Hanguel. He then returned and taught his subjects the alphabet and learned the official langauge writing system.