This sounds like more of a personal question to be answer - sorry
Caliban plots to execute Prosperous so that Stephano can run the island. In spite of the fact that both the words underline concealment of the other, Colonialism is the place one country accept control over the other and Imperialism alludes to political or financial control, either formally or casually. In basic words, expansionism can be believed to be a practice and dominion as the thought driving the practice.
Can you post the passage, so I can see it and then give you the answer.
