In the introduction of an Indians fathers plea hoe does the author show his belief that the teacher does not truly known his son?

The author shows his belief that the teacher does not truly know his son by highlighting the differing perceptions of the teacher and the author on the son's behavior and character. The author points out that the teacher's assessment of his son does not align with his own understanding, suggesting a lack of understanding on the teacher's part. This contrast underscores the author's perception that the teacher's knowledge of his son is incomplete or inaccurate.