The Kra-Dai language family is a group of languages primarily spoken in Southeast Asia and southern China. It includes several major languages, such as Thai, Lao, and Zhuang, which are used by millions of people. The family is divided into several branches, with the Kra and Dai branches being the most prominent. Linguists believe that the Kra-Dai languages share a common ancestry, which makes them part of a larger linguistic classification. These languages are known for their tonal nature, meaning that the pitch used when pronouncing a word can change its meaning. This feature is common in many languages of the region.