This master’s thesis consists of five parts. In the first introductory part, the relationship between man and language, the component of language, and the relation of language, speech and communication are described. Language is a complex and rich system that people use for the purpose of expressing their own thoughts as well as understanding other people's thoughts. In today's interpretations, language is most often described as a human communication system consisting of five components: phonology, morphology, syntax, semantics and pragmatics. Language is primarily achieved through speech, but also in writing, without which modern communication and life are unimaginable. The second part of the paper deals with the preparation of a child for life in the world of written communication, on the development of early literacy (preceded by emergent literacy - the child's reading and writing imitation). Early literacy involves the attitudes, skills and knowledge essential to building formal education, and most commonly includes phonological awareness, vocabulary, narration, interest in the press and the concept of printing and the naming of letters. These phases represent basic linguistic competences, present in the neat speech-language development of children, which is described in the next section. The third part of the paper presents children's speech development from birth to school leaving. Language development is divided into: prelinguistic or preexpressive period and linguistic or expressive period. In order to successfully master the letter and the written communication, the child must possess a certain degree of metalinguistic awareness, which is discussed in the fourth part of this paper. Metalinguistic consciousness implies the ability to pay attention to and reflect on the characteristics of the language. This section describes theories about the development of metalinguistic awareness and metalinguistic abilities; the connection between metalinguistic awareness and bilingualism, the relation of cognitive, linguistic and metalinguistic development, the connection between literacy and metalinguistic aareness, and the development of metalinguistic awareness. The fifth part of the paper contains an overview of the research aimed at establishing the existence of metalinguistic awareness in pre-school children. Research has shown that children have adopted aspects of meralinguistic awareness, thus confirming the results of previous research.