Phonetic symbols commonly used by Mongolians. The initial pronunciation, spelling rules and lines of early Mongolian characters are similar to Uighur, which is called Uighur Mongolian. Among the existing documents written in this language, the earliest one is Ye Song Ge Bei (1225). But so far, there is no document directly recording the early Uighur Mongolian letters. The Uighur Mongolian initials listed in modern Uighur Mongolian works are based on the analysis of Uighur Mongolian documents. It is generally believed that there are 19 letters. There are 5 vowels and 4 consonants/kloc-0. Most letters have three variants: prefix, middle word and suffix. A single letter does not appear at the beginning of a word. There are only two variants: the middle and the end of a word. Vowel letters and consonant letters are closely combined in strokes, and in most cases they are connected together. Spelling is generally based on words, but sometimes a word can be written in two paragraphs. Word order is from top to bottom, and line order is from left to right. There are three kinds of punctuation marks: single dot (equivalent to comma), double dot (equivalent to period) and four dot (used at the end of a paragraph). Uighur Mongolian developed into two branches in17th century. One is Mongolian, which is popular in most parts of Mongolia at present. One is Tote, which is only used in Huilat dialect area. Compared with Uighur Mongolian, the present Mongolian has the following characteristics: the shape of some letters has been improved, which is more convenient for continuous reading; Some letters are written in different ways, representing different sounds; Added letters used in spelling loanwords; The phenomenon that a word is divided into two paragraphs has disappeared; New punctuation marks have been added. The current Mongolian alphabet consists of 29 letters. Five of them are vowels and 24 are consonants. Round-lipped vowels O and u*** use one letter. , u * * * Use one letter. Consonants d and t use one letter variant at the beginning of the word, two letter variants before and after the vowel of the word, and another variant at the end of the word. G and k are written in the same way in feminine words. Mongolian language has played an important role in the development of Mongolian culture and preserved rich cultural heritage through it. Since the founding of the People's Republic of China, there have been a large number of books on politics, economy, culture, science and technology, education and so on. It has been published in Mongolian, including Chinese and foreign masterpieces created and translated by itself, and various newspapers and periodicals have been published. Toth was changed from Mongolian by Zaya Panditha (Namuhai jamsu), a monk in Huilat in 1648. It accurately expresses the phonetic system of Huilat dialect. The alphabet of handbags consists of 3 1 letters. Seven of them are vowels and 24 are consonants. The shape and pronunciation of letters are somewhat different from those of Mongolian now. Use four different letters to represent four vowels with different tongue sounds. Consonants k and g, t and d are also distinguished by different letters. Additional symbols representing long vowels are set, and the double writing form of long vowels is specified.