What's the difference between ancient Mongolian and modern Mongolian?

The difference between ancient Mongolian and modern Mongolian: the modern pronunciation of many words is very different from the syllable pronunciation recorded literally. For example, the word "mountain" is pronounced as "Agura" in ancient Mongolian and "Houlle" in modern Mongolian (UUL in Latin and уул in new Mongolian).

Mongolian has strict vowel harmony rules in pronunciation, that is, harmony is carried out according to vowel tongue position or round lips. For example, in a word, it is either a postvowel (masculine vowel) or a midvowel (feminine vowel). But the front vowel (neutral vowel) and the back vowel or middle vowel can appear in the same word. Morphologically, it is based on the root or stem, followed by additional components to derive new words and change the shape of words; Nouns, pronouns, adjectives, numerals, adverbs, postpositions and verbs all belong to the grammatical category of person, number or case; Verbs belong to grammatical categories such as tense, aspect, state and form. According to structuralism, the word order in a sentence is regular. Usually the subject comes before the predicate, the modifier comes before the modifier, and the predicate comes after the object.

At present, there are nearly three million Mongolian speakers in Mongolia. In addition, a considerable number of people in North Asia of Russian Federation (Republic of Buryatia, Republic of Tuva, Altai Territory and Altai Republic), China and northern provinces of China (Inner Mongolia, Liaoning, Jilin and Heilongjiang) speak Mongolian as their mother tongue.