In this formative research exercise, the process of “Whilst-us evaluation of Entreacto is presented, a didactic material designed in 2016 for the teaching of intonation in Spanish as a foreign language. The central goal was to evaluate its effectiveness in a real teaching context, considering its own objectives: its usefulness to integrate intonation activities in the classroom by the teacher and its impact on students’ motivation. The participants were 4 scholarship students of the FOCALAE program and two of their teachers. With a mixed approach, in a correlational study, the information obtained is analyzed quantitatively and qualitatively. There were 3 instruments of data collection: a Likert type questionnaire, a closed questionnaire and field notes based on observations in class. With the program SPSS (Statistical Product and Service Solutions), levels or ranks were established according to the percentiles of the responses of the Likert questionnaires. The analysis of the qualitative data was done through the open and axial coding of class observations. These results were analyzed together to obtain a better understanding of the experience. The findings suggest that students' levels of motivation vary considerably depending on the variable measured: in class, regarding intonation and on the inclusion of intonation activities in class. On the other hand, the teachers point out that although the level of usefulness of the material was not high, the teachers present a positive attitude towards the teaching of intonation after the application of the material.