During the Song Dynasty (960-1279), the official language of the Chinese court and administration was Classical Chinese. However, there were also various regional dialects and languages spoken by the common people. English did not exist during the Song Dynasty, as it emerged much later in history. Nevertheless, we can attempt to discuss how to express the concept of the Song Dynasty in English.

To describe the Song Dynasty in English, one could say, "The Song Dynasty was a period of Chinese history that lasted from 960 to 1279. It was known for its vibrant culture, technological advancements, and strong central government." This sentence provides a brief overview of the time period and highlights some key characteristics.

Further elaboration could include discussing the political and social landscape of the Song Dynasty. One could mention how it was divided into the Northern and Southern Song periods, with the capital shifting from Kaifeng to Hangzhou during the later period. The sophisticated bureaucracy and civil service examination system implemented by the Song Dynasty could also be mentioned, emphasizing the importance of education and meritocracy.

In terms of cultural achievements, it would be relevant to note the development of Neo-Confucianism during the Song Dynasty, as well as its impact on philosophy and education. One could also discuss the flourishing of literary arts, such as poetry and painting, during this time. Additionally, inventions such as movable-type printing, gunpowder, and the compass could be highlighted, as they had significant impacts on later developments in world history.

It is important to note that when discussing historical periods in a language other than the one in which they originated, some concepts may not have exact translations. Therefore, it is necessary to provide sufficient context and explanation to convey the essence of the Song Dynasty in English.