Pointing to a man, Shailesh said, "His father is the only son of my father."…

Concept: In blood-relation puzzles, first substitute every pronoun ('his', 'my') with the actual people named in the statement, then trace the family link one generation at a time — do not evaluate the sentence at face value.

1. 'His' refers to the man being pointed at, so the statement means: 'The man's father is the only son of my (Shailesh's) father.'

2. Shailesh is male and is a child of his own father, so Shailesh himself is one of his father's sons.

3. Since Shailesh's father has only one son, that only son must be Shailesh himself — no other son exists to be described.

4. Substituting, 'the only son of my father' = Shailesh, so 'the man's father' = Shailesh.

Cross-check: If Shailesh is the man's father, then the man's father (Shailesh) is indeed the only son of Shailesh's own father — exactly what the statement claims — so the deduction is consistent. Hence Shailesh is related to the man as his father.