Children start already adopting language since their birth, but accordingly to some authors even before. This process begins in child's closest surrounding, in most cases this means household, whereas child adopts language spontaneously and naturally. Every child goes through this process and in short period of time and master different lingual stages. Children's primary environment has a strong influence on child's speech and how will child talk in different communicating situations. Inspired by this fact, the main cause of this paper is to find out does children, who grow up in dialect enviroment, speak on their dialect also in educational institutions and how much is dialect present in their spontaneously speech. This paper is divided into theoreatical part and research. The first segment of theoretical part considers adopting language and shows the whole process of child's development of speaking. Next chapter displays lexical development of children with a purpose of how children value words. The process of acquiring lingual sign and appearance of neologisms are also explained and at the end of chapter there are some exercises to stimulate lexical development. The last theoretical part discuss child's language in his closer and wider enviroment and it shows various opinions of many authors regarding the influence of primary surrounding on child's speech. It also discusses dialect and its usage considering main purpose of this paper which refers to presence of dialect in spontaneously speech of preschool children. After theoretical part, in this paper, it is represented a study that has been conducted in kindegarten "Sunčana" in Zagreb and "Konjščina" in Hrvatsko zagorje. The main goal of this study was to examine difference in using dialect in spontaneously speech. The study has been conducted by interviewing children and preschool teachers and short lexical exam. The conclusion is that surrounding has a impact on child's speech and the results have shown that children from Zagorje, where it is spoken typical dialect for that area, use dialect in spountanelously communication, but also in educational institutions more often than children from Zagreb. Therefore, the assumption made before conducting survey, that says that surrounding in which child grows up has a impact on child's speech, was confirmed.