This course aims to familiarize students with the non-typical development of the phonological level of language and the sounds that support it on a theoretical and more practical level. To better understand the non-typical development of the phonological system, the first half of the course covers the typical phonological development both at the level of production and comprehension. The stages presented are early phonological development, the order of acquisition of consonants and vowels, and the types of phonological errors that occur before the acquisition of the phonological system is completed (by the end of the preschool period). The second part of the course focuses on the types and causes of phonological disorders and the procedures for their prevention, assessment, and correction.