Cara M. answered 10/21/19
BA in English, Analytical Writing
I would start by really fleshing out the definitions of each of these terms from your source material. To do this, you could think of a situation for each mode of communication. When would someone use technical communication? What about nonverbal? When do we apply these different modes? When are some useful and others not? Are there situations where we use multiple modes at the same time?
Thinking about each of these modes separately and specifically will help you find the similarities and differences between them. Good luck!