James introduces a man as the only son of the husband of his wife's mother. How is the man related to James?

To determine the relationship between James and the man he introduces, let's break down the statement systematically.

1. Identify the Family Relations:

   • James refers to "his wife's mother". This indicates the mother-in-law of James.
   • The "husband of his wife's mother" is the father-in-law of James.

2. Analyze the Phrase:

   • The phrase continues with "the only son of the husband of his wife's mother". This means we are talking about the only son of James's father-in-law.

3. Understanding the Relationship:

   • The only son of James's father-in-law would be James's wife (if he has one son).
   • Therefore, the man referred to is James's wife, making him James's brother-in-law.

Final Answer

The man is James's brother-in-law.