Geolinguistic analysis of the word form derived from red in Tibetic languages in Khams and Amdo

This article describes how the word form derived from Literary Tibetan red is used in varieties of Tibetic languages in the Khams and Amdo regions. Most varieties use these forms as copulative verb stems, and in most cases, it functions as a factual or statemental (+sensory) evidential form. However, we observe slight differences in its usage, and we can classify its functions across different languages as follows: (A) copulative verb stem, (B) stative verb, and (C) no corresponding words used. Varieties with Types B and C do not use red as a copulative verb stem for the factual evidential; however, in most cases, they also have the factual evidential category, for which a stem derived from another Literary Tibetan word form is used in place of red. The article draws maps of the distribution of the types listed above and interprets their features. The results of this can be used to support an analysis of the development of the use of red in the target region. In addition, we discuss how the factual evidential category developed in Tibetic languages