In a Brazilian second year High School English class, the...

In a Brazilian second year High School English class, the topic of the week is Politeness and Attitude in Questions. To reinforce the lesson, the teacher shows a brief video of two characters asking the same question — “Could you help me with this?” — but with different intonations:

1. In the first version, the speaker employs a friendly, rising-falling intonation, sounding polite and approachable.
2. In the second, the speaker's pitch is flat or sharp, and he sounds impatient, even rude.

The teacher then covers how intonation can alter the attitude that is perceived from the speaker and even with the same words. Students then pair off to practice short dialogues (at a hotel help desk), working on how to adopt intonation to show politeness, surprise, annoyance, or uncertainty. The activity closes with students acting out short role-plays and classmates providing feedback on intonation and communicative impact. As Gilbert (2008) expresses it, suprasegmental features such as intonation that “are of great concern at the intermediate level” and are necessary for assisting “learners to acquire not only correct grammar but also communicative effectiveness”, as said by Celce-Murcia, Brinton and Goodwin (2010). According to the authors, what purpose does intonation serve for the intermediate L2 learner of English?