The book is divided into nine chapters. The first chapter, "Introduction", includes the purpose of the research project, the current status and significance of the research, the design ideas and research content of the project, the research methods, and the main ideas and innovations. The second chapter, "The Origin and Clan Composition of the Karaqin Mongols", argues from different angles that the word "Karaqin" derives from the professional name of the court guard "Xiao Razhen" in the Northern Wei Dynasty; "Karaqin" as a tribal and professional name, mainly from the Kipchak Army and Harachi in the Yuan Dynasty; As an independent and unified tribe, the "Karaqin" was formed in the Ming Dynasty; In the Qing Dynasty, "Karaqin" was the name of a Mongolian tribe and administrative region. The third chapter is "The Use of Mongolian Spoken and Written Languages in the Karaqin Banner of Chifeng City". Social survey and questionnaire survey data show that less than 0.6% of the Mongolian population in Karaqin Banner use Mongolian language. People born in the age group of 70-85 born from 1921 to 1936 belong to the era of transition from Mongolian to Mongolian and Chinese, which is the Republican period; People born in the age group of 55-68 born in 1938-1950 belong to the era of bilingualism, which includes the War of Resistance Against Japan, the War of Liberation and the founding of New China; People born between the ages of 17 and 55 born in 1951-1990 belong to the era of switching to Chinese. It is estimated that in another generation, that is, about 30 years, there will be no people in the Karaqin banner who use the Mongolian language in essence. The fourth chapter is "Use of Karaqin Mongolian Languages in Ningcheng County, Chifeng City". Social survey and questionnaire survey data show that the Mongolian language in Ningcheng County has entered the endangered stage. In endangered language (dialect) areas, where the family is the source of motivating the mother tongue and the society is the motivator of the Chinese language, the actual language ability of community members is, in general, close to the compromise of the probability of using the two languages. The general process of language mode conversion is, first, the development of bilingualism, the suppression of the use of pure Mongolian, and the gradual expansion of the use of Chinese; Secondly, Mongolian has withdrawn from the field of social communication, the use of bilingual language has declined, and the use of Chinese has steadily increased; Finally, there was a complete switch to Chinese. The speed of language mode conversion is faster in towns than in villages, children faster than parents, and cadres faster than farmers and students. In endangered language (dialect) areas, schools are an important position for the protection of mother tongue and mother culture, and when merging schools, they should be treated separately and handled with caution. Chapter 5 is entitled "Use of Mongolian Languages in Karaqin Left Mongolian Autonomous County, Liaoning Province". Social survey and questionnaire survey data show that Mongolian speakers account for 15.9% of the total Mongolian population in Karaqin Left Mongolian Autonomous County, and less than 10% of the actual users are real. The Mongolian language usage model in Karaqin Left Mongolian Autonomous County transitioned from Mongolian monolingualism to Mongolian-Chinese bilingual mode before the founding of New China, and from the beginning of the founding of New China to 1979, and then from Mongolian-Chinese bilingual to Chinese monolingual. The Mongolian language in the Karaqin Left Mongolian Autonomous County has been interrupted in use and has become an endangered indigenous language. Chapter 6 is entitled "The Influence of Geographical Distribution and Population Movement of the Karaqin Region on Ethnic and Linguistic Contacts". Data from the Natural Village Gazetteer Database show that migration has a significant impact on the formation of ethnic contacts and ethnic composition patterns in the Karaqin region, and ethnic contacts and ethnic composition patterns are the most important social factors affecting language contact and language transfer process and progress. Pingquan County began to settle early and on a large scale, and Mongolian villages became a few isolated islands, and in the marginal islands, the Mongolian language was preserved and passed on to varying degrees based on natural villages inhabited by Mongolians. Karaqin Banner migration began early, but due to the restriction of land ownership, the formation of a Mongolian-Han mixed living model, the degree gradually deepened, the use of both languages became a natural selection, the Han population gradually dominated, and the trend of Chinese replacing Mongolian began to form. The migration of Ningcheng County began early, thanks to the support of the Qing court and special development agencies, the immigrants could build villages on a large scale and independently and develop and use the local land and mountains, the living mode was separate, the Mongol and Han ethnic groups kept one side, the degree of mixed living was low, and the Mongolian villages inhabited better preserved the Mongolian language. The migration and living patterns of the Karaqin Left-wing Mongol Autonomous County were deeply affected by the current situation, with the Mongols and Han naturally mixed before the Kangxi Dynasty, and the Han immigrants predominantly after the Qianlong Dynasty, and there was an adjustment process after the founding of the Republic of China and New China, and the degree of mixed living deepened, but not as good as the Karaqin Banner. In the natural villages inhabited by Mongolians, the Mongolian language is better preserved than the Karaqin Banner, but not as good as in Ningcheng County. The data of the "Natural Village Geographical Names Database" also shows that the Mongolian natural village geographical names in the Karaqin area are classified according to their meanings, including four types: physical geography, clan names, occupational division of labor, and settlement households. The natural geographical village name shows that the Karaqin people are mainly mountain settlements; Clan names show that the Karaqin tribe was formed by the fusion of many clans; The name of the village with occupational division of labor shows that the Kalaqin region once had developed animal husbandry, hunting, mountain and forest management traditions, and agriculture and other occupations were gradually developed; The name of the settlement household type shows that the Mongolian villages in the early days of the Karaqin region were mainly 3, 5, 7 and 8 households, and the scale was very small. The name of the natural village of the same name is preceded by a specific qualifier, which is a horizontal expansion form of the natural village, and naming the administrative unit of the natural village at the level above the resident core village is the vertical expansion form of the rural management network. The sinicization of Mongolian place names in the Karaqin region has different processes such as transliteration, transliteration and transliteration, paraphrasing plus transliteration, paraphrasing, two parallelism, and name change. The evolution of geographical names is a type of linguistic evolution. Chapter 7, "Research on Mongolian Bilingual Education in the Karaqin Region," argues that the use of spoken and written languages is deeply constrained by the state system. The combination of the universal function of a particular language and the political power of the state to produce linguistic authority is reflected in the choice of school language and its arrangement order, and the state's regulation of spoken and written language. Language and writing education is closely related to the country's education system and policy operation mechanism. In addition, language education is inextricably and closely related to the proportion, distribution and changes of the population, with the economic support capacity of the population for language education, and with the expectations of the educated for social development. Chapter 8 is entitled "The Impact of Interracial Marriage on the Evolution of Language Use Patterns in the Karaqin Region." Intermarriage has an important influence on the evolution of language patterns, but it is not a determining factor. The influence of interracial marriage is mainly manifested in the fact that Han mothers bring Chinese into the family and affect the family language patterns of their children. The determinant of the evolution of language patterns in intermarried families is the socio-linguistic environment, of which working language and neighborhood language are the most important factors. Mongolian language education is of great significance to the maintenance and application of Mongolian language, but if the trend of sinicization in the social environment is strong, then Mongolian language education in schools will eventually not be able to resist the pressure from society. The basis for the evolution of the view of marriage and language is social practice. There is a history of interracial marriage or interracial marriage in the family, and family members who use Chinese more in society will generally approve or tolerate interracial marriage and switch to Chinese. Families of all language patterns, with or without a basis in practice, endorse bilingualism as a verbal strategy acceptable to all parties in intermarried families. Chapter 9 is "Summary and Theoretical Exploration". The case study can be summarized as follows: (i) The establishment of a unified state and socio-professional roles are important factors in the integration of clans into tribes. (ii) The degree of ethnic contact depends on the mode of contact between ethnic groups, geographical location and migration patterns. (3) Land ownership changes with changes in class relations between and within ethnic groups, and it is the person who lives on the loess who truly protects that land. (4) The sinicization of personal and geographical names is governed by the law of language evolution and language transfer. (5) Language usage patterns, types, and language conversion stages and speeds. The use mode of Mongolian languages in the Karaqin region is divided into three categories: retention, transfer and bilingualism. Bilingual forms are further divided into Mongolian endangered type, Mongolian weak type, and Mongolian decline type. From the establishment of the Karaqin banner to the 30s of the 21st century, a total of less than 400 years, the first 300 years, Mongolian Chinese after a long period of contact, Mongolian gradually lost its dominant position, the next 100 years, Mongolian through Mongolian monolingual, Mongolian and Chinese bilingual, quickly transitioned to Chinese monolingual. Throughout the Karaqin region, the Mongolian language has become endangered due to the interruption of the social use of the Mongolian language. (6) Factors affecting the speed of language conversion. The key factor influencing the speed of language conversion is the pattern of ethnic contact, especially the pattern of residence. With the predominance of the Han population, the trend of replacing Mongolian with Chinese began to take shape. The living mode is separate, the degree of intermingling is low, and the Mongolian language is better preserved in Mongolian villages; The practice of Mongolian and Chinese language contact in the Karaqin region proves that the key factor affecting and determining the transformation of language use mode is not the absolute number of users, nor the proportion of users in the total population, but the living patterns and the degree of intermingling and interaction of different ethnic groups in the resident society. A natural village of a certain population size is the most basic social form in which a linguistic society can be formed and preserved. The language usage field is an important factor affecting the transformation of language usage patterns. In the mixed community of Menghan and Han in the Karaqin region, the family is the source of motivating the mother tongue, the society is the source of Chinese motivation, and the actual language ability of the community personnel is, in general, close to the compromise of the utilization rate of the two languages. The degree of regional, socio-economic and cultural development affects the transformation of pragmatic patterns. In terms of the speed of language mode conversion, towns are faster than villages, children are faster than parents, and cadres are faster than farmers and students. Occupation has an impact on changes in language usage patterns. Among the current Mongolian languages in the Karaqin region, the highest degree of Chinese use is made by cadres, followed by parents and teachers the lowest. Age, rank, and gender constraints in family language change from scene to scene. It turns out that the decisive factor in the formation of current language use patterns is the socio-linguistic environment, and the family language changes with the socio-linguistic environment. The influence of socio-linguistic environment is first reflected in the language application patterns of fathers and juniors, and then affects grandparents and mothers, gradually penetrating into family language. (7) Language conversion and cultural transfer are not equal, and language selection and language sentiment evaluation are inconsistent. (8) Language education and language conversion. Language and writing education is closely related to the country's education system and policy operation mechanism. The use of spoken and written languages is heavily constrained by the national system. Language education is inextricably and closely related to the proportion, distribution and changes of the population, with the economic support capacity of residents for language education, and with the expectations of educated people for social development. This study finds that Mongolian language education is of great significance to the maintenance and application of Mongolian language, but if the trend of sinicization in the social environment is strong, then Mongolian language education in schools will eventually be unable to resist the pressure from society. (9) Interracial marriage and language conversion. Intermarriage has an important influence on the evolution of language patterns, but it is not a determining factor. The chapter also discusses several basic theoretical issues related to the phenomenon of language contact.（AI翻译）