If the man had no will, his immediate next of kin would be his father in most jurisdictions. You can check the laws of intestacy for your state at the related question link provided below.
If a man dies and is survived by his father and sister, the father would likely inherit the man's assets as a direct blood relative. In the absence of a will specifying otherwise, the father would typically be the primary heir according to intestate succession laws.
Your mother's sister would be your aunt. Your father's sister would also be your aunt.
She would be your step-sister
Your father's sister is your aunt and her husband is your uncle. Some would say "uncle by marriage."
Generally, a person who kills another cannot benefit from the death. For example, a husband who murders his wife cannot inherit from her estate. It would pass to her other heirs. A son who kills his father cannot inherit from his father's estate. A sister who kills her brother in order to get his inheritance will lose her right to benefit from the estate. All the above mentioned murderers must be found guilty in order to be barred from inheritance.
You would call your wife's sister your sister-in-law. If your wife would have a brother he would be your brother-in-law. It is the same thing for a husband's siblings. Your wife's mother would be your mother-in-law. Her father would be father-in-law.
Laws vary. Generally, the surviving spouse and the children inherit in an intestate (without a Will) estate. If you were not married to the father then his children would inherit his estate. You can check the laws in your jurisdiction by performing an online search for "intestacy laws- your jurisdiction".
Your father's sister is your, paternal aunt,and your mother's sister is your, maternal aunt.Father's sister is your aunt.
I would think that would make him your great grandpa!
Your mother or father would have to adopt them. Answer You can make her a sister of the heart. That's it.
Her father, unless the son and his sister have different fathers which would make him nothing to his son's sister.
You not related to that person.
He would be your cousin, or your father's nephew.