The extant research on linguistic interactions in scientific inquiry has focused solely on the quantitative analysis of the verbal interactions among the students and poses limitations to investigating the internal characteristics of such interactions. This paper presents connections among the members of a student group based on its interaction patterns and size to find out the ideal size of a student group in order to allow the student to have optimum participate in the group interactions. In this regard, this study sought to analyze the patterns of verbal interaction that occur during inquiry activities using social network analysis (SNA). 144 first-grade middle school students in science class in South Korea were participated and organized into small groups with three to six members each, and the language network of the 32 small groups that were thus formed was analyzed. The conclusions of this study are as follows: (1) the groups of students formed in school for learning activities should consist of only three members each to avoid alienation among the members, and (2) in student groups with four or more members each, there are many participation-type interaction structures that can be used if there is a group leader. The interactions among students within small learning groups can allow them to fully understand other students’ opinions which may otherwise not be very clear, and to solve a problem after considering all the opinions students have expressed, and support the effective learning by positive interactions among the members.