请修缮这段文字要求表达要清晰语法要准确。commitment speech act refers to the speaker makes a commitment to a certain act that he or she will perform in the future that is the speaker undertakes a certain obligation to do

The term "commitment speech act" refers to a situation where a speaker makes a commitment to perform a certain act in the future, thereby undertaking an obligation to do something. This definition was provided by Wen Jian in 2016. The verbs used to express such commitments include "guarantee", "promise", "refuse", and others. It is uncommon to see commitment speech acts in public service announcements. However, by using promises, public service announcements can attract the attention of the audience and build their trust in the effectiveness of the message