What is the impact of the point of view in at least two different chapters of the first half of Pocho? Focus on the narration shifts. What are some of the immediate effects of those narration shifts?
This is a difficult question to answer as it is a bit confused in meaning. The narrator of each chapter is the same third-person narrator, so the tone remains the same. Thus there is no narratorial shift as far as the narrator goes, which is what is usually suggested by this question.
The shift that occurs relates to the changes between the lives being revealed by the narrator. The effects of these shifts are directly related to the emotions and experiences of the people told about.
The difficulty with this question is that "point of view" refers, in fact, to narratorial point of view, and would only demonstrate a "shift" if the narrator changed, for example, from a third-person to a first-person or from one definitive third-person to a different yet equally definitive third-person narrator.
As it is, the shifts are in emotion and experience portrayed under the constant point of view of the consistent and recognizable third-person narrator. An example of the shifts of character mood and experience (narrators associate with tone, not mood) is the difference between Consuelo and Juan Rubio. The shift illustrated below shows a change in mood between hard, cold commanding callousness [Juan] and soft, unformed confusion [Consuelo].
Juan: As [the girl] walked past [Juan], he called, "Come here!"
She hesitated in mid-stride. The words, although spoken in a low voice, had been commanding. "Que quierres?" ...
"I have been watching you. You please me."
"So? I please many men," she said ... and made as if to leave.
"Sit down and drink with me," he said.
She knew she should go, but something about him frightened her and she lost her composure.
Consuelo: It was cool, as it is at night in the desert, and she wrapped her shawl around her shoulders and stepped outside. She took a few steps, and suddenly she did not know where she was going, or for what reason she was outside the house. She looked at the lamp in her hand for a long moment, then set it on the ground and wandered aimlessly.