This paper examines the rhythm and the management of classroom interaction as an important constituent of a teaching-learning process. Twenty-three lessons in 12 classes (four 2nd grades, four 3rd grades and four 4th grades) of state primary schools spread all over Italy were observed and videotaped for a total of 15 hours. The descriptive analysis of the collected data revealed a transformation of children's and class interactivity and a change in the use of turn-taking strategies (overlaps, interruptions and pauses) from 2nd to 4th grade. Additionally, it showed that: (1) speaker after overlap changes according to the type of overlap; (2) teachers differ from children in their turn-interrupting strategies (teacher interrupts with supportive and silent turns, whereas children with failed or simple interruptions); (3) log-linear analysis revealed that the next speaker was correlated both with the first speaker and pause duration, but these correlations were independent between them. For a more accurate interpretation of the results various aspects characterizing educational and school interaction were taken into account. (Contain 8 tables, 2 excerpts and 2 notes.)