An ability to use seperation marks at the end of the senAn ability to use separation marks at the end of the sentence is one of the determining factors of successful written communication. In this paper the ability to use separation marks at the end of the sentence is discussed according to the results of the research. Two researches were made to distinguish ability mentioned above. The goal of the first research was to find out, how pupils can use separation marks at the end of the sentence according to the teacher's intonation. The goal of the second research was to find out, what marks pupils use in the created works in consider in the situation of communication. The results of the research confirmed the hypothesis that pupils of the 2nd and the 4th grade are able to use proper separation marks at the end of the sentence when sentences are read by the teacher. Though in creative works pupils mostly use declarative sentences that do not reveal the situation of communication. According to the information received from conversations with teachers and from my own experience I can assert, that ability to express situations of communication using proper separation marks at the end of the sentence in creative written works can be developed: - paying regular attention to the sense of marks in the folklore, belles-lettres texts; - dramatizing texts mentioned above; - reading texts in roles; - using interactive teaching strategies.