This master’s thesis consists of four parts. The first part describes children’s language development. It is important to note that speech development does not begin with the child’s first words. It begins while the child is still in the womb, from where it listens to its mother’s voice and distinguishes it from the voices of others. When it comes to adequate speech development, developing preverbal communication is essential. Preverbal communication consists of four phases; it begins at birth and ends with the child’s first utterance of a meaningful word. The first word is most often pronounced between the 12th and the 18th month of the child’s life. The second part deals with literacy development and early literacy. Literacy development is a complex, long-lasting process that requires instruction and begins before formal education. It can be divided into the reading and the pre-reading period. The pre-reading period is critically affected by early literacy, which comprises abilities and skills that are an indicator of reading skills in later educational periods. A certain level of metalinguistic awareness is necessary for the child to be able to master reading and writing successfully. The third part, therefore, discusses metalinguistic awareness –the ability of an individual to think about language, use its structural features and treat it as an object of thought. The fourth part is an account of our research, which aimed to determine the extent of metalinguistic awareness of preschool-age children. Our research has shown that preschool-age children’s metalinguistic awareness is only in the beginning stages of its development, which is consistent with numerous theories and studies that have been so far conducted.