Scientific knowledge is a set of theoretical understandings based on scientific thinking. There are clear methods of scientific study of the essence of complex, diverse and colorful phenomena, laws of development of nature, society and human thinking. They determine the direction of scientific research. Language and speech together are a common subject. All their principles are equally important because neuropsycholinguistics is also responsible for the relationship between language and speech. There is always something new in this field of science. Cognitive principles - the brain and its relationship to language - are important for language acquisition and categorization. Although this work is very complex and difficult, a person can be healed with a good word. Because the word is also a source of energy in controlling the mind. This is one of the almost unsolved problems of neurolinguistics. The brain is a mysterious world, if we study it from the point of view of the influence of speech, the way we perceive language, the way we speak, it becomes easier. With the development of neuropsycholinguistics in recent years, there is an increasing need for in-depth knowledge of the nature of these phenomena.