How would you explain ‘one quiet assertion’ in the context?
Alejandro, the village boy, almost never speaks. Yet claims he wants to learn English. One quiet assertion at a time, he begins: I am. You are. His room is the one at the opposite end of the guard house, but he comes to this one every morning at four, after finishing his shift of pacing the roof with his rifle cocked in darkness. This room that has housed no secrets up to now, except for a box of things hidden under the bed: a small stolen idol. A partly written, entirely dreadful novel. The little woven finger toy called a trapanovio, souvenir of a remarkable humiliation.
How would you explain ‘one quiet assertion’ in the sentence: One quiet assertion at a time, he begins: I am. You are?
PS: It’s form The Lacuna by Kingsolver.