However when Prospero is annoyed by this, he quickly apologises.
Caliban frets constantly at being kept under, while Ariel generally puts up with it.
At the play's close a chastened Caliban declares, 'I'll be wise hereafter, And seek for grace' (5.1.294-295) as part of the general reconciliation engineered by Prospero. He is a 'monster' (2.2.66), a 'moon-calf (2.2.107), a 'born devil' (4.1. Because his father was a devil, Caliban is supernatural like Ariel, but unlike that airy spirit, he has no supernatural powers.
He is more like a debased human than like any other supernatural creature in Shakespeare.
Ariel, we learn, is a sort of disembodied spirit capable of invisibility and even taking on multiple forms at once; in contrast, Caliban is associated with materiality and the body.
Prospero calls Caliban not only a “slave” but also “earth,” establishing a hierarchical relationship between his two servants that is at least in part informed by their material conditions.
During the first meeting, Caliban comes across as very savage and immoral.
Prospero, when approaching Calibans lair, says disdainfully, ...[he] never/Yields us kind answer, meaning Caliban never responds with respect.
Caliban grumbles all the time at his servitude; he resents Prospero deeply and eventually leaves him for another master, and plans to murder him, although he is foiled in this.
Ariel appears to be far more highly valued as a servant by Prospero than is the savage Caliban, but Ariel, too shows some signs of discontent with his servitude, reminding Prospero quite forcefully at one point of Prospero's promise to free him.