Abstract: The object of the study is the infinitive of the German language, and the subject is its semantic, structural and functional characteristics, which make it possible to interpret it as a verb form. The authors consider in detail such aspects as the specificity of the infinitive expression of the verbal categorical meaning, which brings it closer to the noun; structural division and microsystem of infinitive forms of the modern German language. Morphological features of the infinitive are considered through the prism of historical changes in the structure of the word in the German language. The authors pay special attention to the syntactic behavior of the infinitive. At the same time, the authors pay special attention to the multifunctionality of the infinitive, which is maximally identical to the nominal parts of speech. At the same time, the authors note the manifestation of the verb character of the infinitive in the ability to form a verb group. The methodological basis of the work is based on a systematic approach to the interpretation of linguistic phenomena in synchrony and diachrony. The theoretical basis of the research is the fundamental principles of general, comparative historical and Germanic linguistics. The comparative method and the method of distributive analysis were used to identify the functional potential of the infinitive and innovative phenomena. The main conclusions of the study are to identify the complexity of interpreting syncretic units to which the infinitive belongs. It was found that during the development of the German language, the infinitive gradually entered its verbal system, losing nominal grammatical features, such as the case paradigm. At the same time, the infinitive acquired verbal signs, as a temporary and collateral meaning. A special contribution of the author is the conclusion that the dual nature of the infinitive, which determines its peripheral position, is the basis for expanding its functional potential, which contributes to the participation of the infinitive in the formation of new grammatical structures/forms. The novelty of the study lies in the identification of such a function of the infinitive as participation in the formation of verb groups, where maximum proximity with the final verb is manifested.