The use of improper language is anchored in everyday life and is becoming more and more common. Therefore, as educators, we must be aware that we are giving children a model of speech and thus directly influencing development of language ability (Kranjc and Saksida, 2001). In the theoretical part I described language, speech and communication. I presented the roles and types of the Slovenian language. In the last chapter I focused on the use of the Slovenian language in kindergarten and school. The goal of my empirical work was to investigate possible differences in the use of Slovenian language among preschool teachers in kindergarten and 1st grade. I was interested in whether the educators are paying attention to the improper use of Slovenian language in their working environment, if they are continuously proficient in the field of using the Slovenian language and whether they feel competent in all forms of communication. I also wanted to explore possible differences in educators use of the Slovenian language in kindergarten and school. While collecting data, I used a survey questionnaire, which was distributed to 110 educators, kindergarten staff and preschool teachers in first grade of elementary school. Results were analyzed, converted into percentages and presented with column diagrams. I have found that educators are paying attention to the irregular use of the Slovenian language. Most respondents pay attention to the errors in the use of duality, decantation, use of dialects and slang expressions. Educators at the kindergarten also warned about frequent use of diminutives. I have found out the differences in usage frequency of the literary language between kindergarten and first grade educators. Compared to kindergarten preschool teachers, those in first grade are more likely to use literary than non-literary language. Most educators feel competent and do not detect any problems with their writing or speaking. Preschool teachers from kindergarten have more problems at speaking, while 1st grade preschool teachers have more problems at writing. In most kindergartens and schools educators did not attend seminars or training intended exclusively for the use of Slovenian language at the workplace. The lack of professional training is the second most common cause for the occurrence of improper use of Slovene in kindergartens and schools. Most educators believe that the main reason for the inappropriate use of Slovene in kindergartens and schools is the inability to use the literary language in everyday life.