This article is devoted to the study of the development of agriculture in China during the reign of the Song Dynasty. The interest in this period is caused by the fact that the Chinese managed to get out of the economic crisis that began at the end of Tang's reign. One of the reasons of the rapid economic recovery is that Song agriculture was innovative for its time and created the economic base that not only helped to overcome the economic crisis, but also provoked population growth, trade and economic development. In addition, under this article is dedicated to the study of the speech acts of gratitude in the Vietnamese language, based on the theoretical foundations of speech act theory. The aim of the work is to identify the structural-semantic and pragmatic characteristics of expressions of gratitude, as well as to determine the differences in the functioning of direct and indirect forms of this speech act. The empirical basis of the research is a corpus of texts containing fragments of academic, literary, and journalistic literature in Vietnamese, created in the 20th-21st centuries. The analysis applied contextual, componential, and interpretative methods, which allowed for the identification of both explicit and implicit forms of expressing gratitude. The results demonstrate that the speech acts of gratitude in Vietnamese are characterized by a wide structural variability and a high degree of pragmatic differentiation, which confirms the importance of considering socio-cultural factors when studying the communicative behavior of native speakers of this language.