Syncretism has become the subject of various fields of science. Especially, its properties in the field of aesthetics, art criticism, and cultural studies have been studied to the maximum. It means that linguistics will also need to rethink the function of syncretism. The author of the paper touches upon the problem of syncretism in linguistics. The main purpose of the research is to draw attention to the fact that syncretism refers both to the morphological structure of the phenomenon and the syntactic construction. Most scholars in Kazakh linguistics recognize syncretism as a one-sided phenomenon. And its traces in the syntax remain unnoticed. In this regard, the definition of the term in the syntax indicates the relevance of the paper. And increases the theoretical value.This issue was raised as a separate issue not only in Kazakh but also in other languages. The author proves this by the conclusions of scientists of the Russian, German, and French languages. The features of the connection of the speech structure in the paper on the path of narrowing or expansion determine the syntactic function of syncretism. Particular attention should be paid to the phenomenon in the connections of sentences, namely, a simple sentence from the point of view of formality, a complex object sentence from the point of view of conveying judgments, or, conversely, determines the importance of this task. And this defines a new direction of the syntax of Kazakh linguistics.The study also pays attention to the diachronic nature of linguistics. The reflections of Russian and other foreign scientists indicate that the topic has remained at its initial stage. This is proof that the issue being raised is still important.The conclusions set out in the paper will contribute to the further development of the field of linguistics. The application of the results of work in educational institutions is of practical importance. After all, any language unit must reach the consciousness of the recipient.