sibling query?

Question

Can someone please clarify a issue that i have been wondering about, that is say i have a sister or brother by my mother, and both of us has different dads, yet if my brother or sisters dad has other children, who is my brother or sisters, brother or sister, what relative does it makes them to me.

but what if the mother is the same, but my brother or sisters dad has other children with another women, that my brother or sister calls her or his brother or sister, what does that make them to me.

OK say for example what if my stepmom had a child for my real father, them they split up and she had a child for someone else, which then become the sibling of my sister or brother, what does it make them then, is there any sibling connection, or blood connection.

Answer 1

If you share the same mother but not father then you are step sister or brother . If you dont share either mom or father then you are not related at all . good luck .

Answer 2

If you have the same mother, but not father, you are half-brother/sister, not step sister/brother.
If you have the same father, but not mother, you are also half brother/sister.
If your mother remarries to a man who has his own children, they would be your step sister/brother.
If your half brothers father has children by a woman, not your mother, then they are of no relation to you.