The first step is to choose a conversation as an example. The conversation must take place in a context where one person is more powerful than the other, e.g. parent + small child, interviewer + interviewee, doctor + patient.
You would then analyse the language that each person uses, and pick out the forms of speech that reflect the inequality of power.
(For instance, when old people are in hospital, nurses often address them by their first name, like children. The old people however are likely to call the nurse "nurse".)