The subject of theoretical grammar and its difference from practical grammar

The following course of theoretical grammar serves to describe the grammatical structure of the English language as a system where all parts are interconnected. The difference between theoretical and practical grammar lies in the fact that practical grammar prescribes certain rules of usage and teaches to speak (or write) correctly whereas theoretical grammar presents facts of language, while analyzing them, and gives no prescriptions.

Unlike school grammar, theoretical grammar does not always produce a ready-made decision. In language there are a number of phenomena interpreted differently by different linguists. To a great extent, these differences are due to the fact that there exist various directions in linguistics, each having its own method of analysis and, therefore, its own approach to the matter. But sometimes these differences arise because some facts of language are difficult to analyze, and in this case the only thing to offer is a possible way to solve the problem, instead of giving a final solution. It is due to this circumstance that there are different theories of the same language phenomenon, which is not the case with practical grammar.