The article shows that the origins of most doublets of the Kazakh language can be found in the works of the intelligentsia of the early twentieth century, as well as in the texts of the Kazakh newspaper. The Arab-Persian words used in the "Kazakh" newspaper mean that they are one of the prerequisites for the appearance of lexical, phonetic doublets, variable uses in the modern Kazakh language. The written models of reciprocal words of the early twentieth century differed from the written models of the modern Kazakh language. Therefore, in order to clearly see the differences in the writing, in the examples given, the spelling patterns of that time were partially preserved. Thus, there is an opportunity to compare linguistic facts.