If your wife's son is also your son, then he is your brother's nephew and your brother is his uncle.
If your wife's son is a child from a previous, or subsequent marriage and is therefore not your son, he is not related to your brother unless you have adopted him. If you have adopted him, the relationship is the same as if he were your biological child.
granddaughter
the son would be the nephew
Great uncle / Great nephew
No because that would be your cousin
Step-brothers
Your grandson is the great-nephew of your brother.
Yes, she did. She had the relationship of a mother that a mother has with her son. As most mothers do.
Your younger brother's wife's sister's daughter would be your son's cousin.
i suppose so. if your a redneck...cousins are free game
Well, you are the brother in law to your wife's brother. There is no real title for your brother to her brother, they can be considered extented family members, though.
Your brother would be your son's daughter's great uncle and your son's daughter would be your brothers great niece! Hopefully that makes sense :)
Your half-brother...