The researcher, at his position as a lecturer and a secretary of the youth union, tries to investigate how the way people use words and structures influences the effectiveness of communication. In this case, he would like to know how using correct vocatives and imperative structures results in making requests to members of the youth union at his college, most of whom are students. The study was conducted in the contexts of regular meetings or meetings for some specific purposes mentored by the researcher, the youth union secretary of the college. Methods used were observing, interviewing and analyzing the data collected from the responses of participants. The results showed the suitable use of vocatives and imperatives positively affected the communication purposes in terms of the efficiency of the activities needed to be done, the participants’ willingness and their motivation in conducting the activities.