In the 19th century, the golden age of biology, the open and evolving system of living organisms carried a lot of weight. Therefore, traditional linguists also took biology as a model of language. Language was seen as a living creature that could grow and change – alive or dead. The change has led to the degeneration of today's language - spoken language, so traditional linguists cling to the principle of purest form in order to grasp the correctness of language. The purest form is the written language based on the study of Latin and Greek. From the belief that Latin and Greek are the root of all languages, arises the principle of universal grammar – the idea that all languages ​​are built on a common language. Thus, using language that does not correspond to universal grammar patterns is also degeneracy. Traditional linguists have little interest in the structure of language but spend time studying grammatical forms, such as defining parts of speech or word order, because they believe that language is a set of rules . The study conforms to diachronic study – the study of the event as it evolves over time – by comparing language changes from ancient times to the present day. As a result of diachronic study, there are only things right and wrong in language use, since traditional linguists attempt to prescribe directions by sticking to the rules of precise language use . Therefore, using language that does not correspond to the rules of universal grammar is unacceptable. The aim of the traditional grammar method is to appreciate the aesthetics of the language and not to communicate with each other. Traditional linguists are concerned that the use of its structure ...... middle of paper ...... does not take into account the meaning of the representation, making it possible for sentences to be misunderstood. There are other differences between these two theories. Although it is easy to use L1 in traditional teaching to make students understand what the teacher said, the lesson itself is very tedious. On the other hand, using the L2 in structural teaching is very advantageous but it requires a lot of time. Because L2 is a whole new world for students, so they need more time to get there. However, many types of equipment, for example tapes recorded with native speakers, sound laboratory rooms, visual aids, are necessary in teaching to help students achieve the goal of structuralism. Although there are some drawbacks, there are some virtues to both theories as well. Because there is nothing in this world that is perfectly created.