This school exaggerates the absoluteness of phonetic laws and fails to realize the geographical and structural unity of language and dialect. In language research, atomism is used to study language phenomena in isolation, with scattered materials and lack of systematicness. This school focuses on the personal factors of language and ignores the social factors of language, so it is difficult to study the ontology of language in depth.

Of course, the contribution of the New Grammar School in the history of linguistics is indelible. It summarizes the achievements of comparative linguistics and historical linguistics in the19th century, and indicates the birth of structuralist linguistics in the early 20th century. This school is also called "the first school of modern linguists". Bruggeman and Delbrouck's Comparative Grammar of Indo-European Language and Paul's Principles of Language History are valuable linguistic documents.