Modality- High and Low within a Speech

Modality applies to my speech because if I was to have high modality through out my speech it would make me look and sound enthusiastic about the topic that I have chosen and the side I have taken. Having high modality means that I believe strongly about the side I have taken on the topics I have chosen by using words such as "must" and "always" to say my point of view. But if I were to have low modality this would mean that I would be more tentative within my speech by using words such as "may" and "could". These words show that I am not very certain about the side I have taken and the argument that I am imposing.