half-sister A half sister is a sister who is related to you by only one parent. She shares half of your blood. You share one parent either a father or mother with her. stepsister A step sister is the daughter of your stepfather or stepmother by a former partner. There is no relation by blood. You are only related to your stepsister by the marriage of one your parents. I have two stepsisters. They are the daugthers of my stepfather. My mother is their stepmother.

Don't worry Erik ,I won't hate you for that ;). On the contrary I 'd like to thank you for the clarification. Iwan got the correct answer from you. However * for Iwan to know* my definition is correct except for the fact that this very definition doesn't make them the same.

I want to add some clarity here. (Cherry, don't hate me!) The term "half sister" is not the same as "stepsister". I think it was explained correctly, except for this. Mary was part of another family, not mine. Then, her mother and my father got married. Mary is my stepsister. Mary was part of another family, not mine. Then, my mother married her father. Mary is my stepsister. Mary did not exist. A woman married my father after he divorced my mother. My father and this woman had a baby, Mary. She is my HALF SISTER, because we share the same father. Mary did not exist. A man married my mother after my father died. My mother had another child, Mary, with this man. Mary is my half sister, because we share the same mother. I did not exist. Mary's father had an affair with a woman and got her pregnant. This woman gave birth to me. Mary is my half sister, because we share the same father. I did not exist. Mary's mother dated my father after both of their spouses died. Mary's mother got pregnant and gave birth to me. Mary is my half sister, because we share the same mother. In short... "step-" means the family member shares NO BLOOD with me. "half" means the family member shares ONE PARENT'S BLOOD with me. For this reason, you cannot have a "half father" or "half mother", only a "stepmother" or "stepfather". And notice, there is no hyphen (-). Also, "half" uses a space following, while "step" gets joined to the next part of the word.

Hello Iwan, -step is a prefix denoting connection between members of a family by the remarriage of a parent and not by blood. *A step-sister is on'e stepfather's or stepmother's daughter from a previous marriage. A stepfather* in case you don't know it* is the husband of one's mother by a later marriage, like stepping for the real father; same with stepmother a wife of one's father by a late marriage. * A half-sister means the same actually. It is the sister who has only one parent in common with one.So she is also one's step-sister. Her mother or father, one of them is one's step-parent.