No. Your son-in-law's brother may be a son-in-law if he is married, but he is not your son-in-law.
No, your son-in-law is married to your daughter and his brother is not your son-in-law, but simply your son-in-law's brother or your daughter's brother-in-law.
If your sister-in-law is the wife of your brother, she is the mother of your brother's son. Her son-in-law would then be the brother-in-law of your brother's son. If your sister-in-law is your spouse's sister, her son-in-law is not related to you or to your brother's son.
The singular possessive form of "son-in-law" is "son-in-law's."
"Son-in-law" is spelled as indicated, with a hyphen between "son" and "in-law."
The singular of "son-in-law" is "son-in-law." It remains the same in both singular and plural forms.
Your son-in-law's brother's son is not related to you, but is your daughter's nephew.
No. A son-in-law is a contemporary.
It is written as 'son-in-law.'
The possessive form of the compound noun son-in-law is son-in-law's.Example: My son-in-law's name is James.
Sons-in-law is the plural for son-in-law.
The plural of "son-in-law" is "sons-in-law."