Caliban's monologue in Act I Scene 2 of Shakespeare's play The Tempest is written in English. In this monologue Caliban claims ownership of the island, as it had been property of his mother, Sycorax. He also claims that Prospero, when shipwrecked on the island, feigned kindness to Caliban, but has since imprisoned Caliban in a cave and turned him almost into a slave. Prospero retorts that Caliban attempted to rape his daughter Miranda in justification for this reversal. Caliban suggests that he was legitimately trying to populate the island with his own offspring.
This passage is central to postcolonial readings of the play and filled with a sort of situational irony. Although Prospero has been dispossessed of his own Dukedom, and considers such usurpation unjust, he has no qualms about usurping Caliban's right to the island and enslaving him. In this way, Prospero seems a microcosm of the way European cultures acted towards many nations in Africa, South America, and Asia.
Given Prospero's power as a magician (the dramatic equivalent of European technological superiority), Caliban's only recourse is language, but even in that he does not have a level playing field, as he must communicate using the alien language of his oppressor, and he protests in the following lines:
You taught me language, and my profit on ’tIs I know how to curse. The red plague rid youFor learning me your language!