"Ta belle-mère est la femme de ton père."
Translation:Your stepmother is your father's wife.
I think Duo was wrong in translating demi-frère as "step-brother" - a half-sibling is related to you by blood through only one parent, meaning that it's a child born to one of your parents with a different spouse than your other parent. Step-relatives and in-law relatives aren't related to you by blood at all.
And that's what the Chinese did, and it's hella confusing. (In Chinese, every single relative has their own word: i.e.: sisters of your mother, sisters of your father, brothers of your mother, brothers of your father, sons of each one of the mentioned above, daughter's of... you get the idea).
I'm sorry, this started out as your father-in-law and my mother-in-law, and suddenly belle-mere means stepmother. And more to the point when I went back to the base section to look for the guidance......there wasn't any. Could somebody please explain how belle-mere means mother-in-law AND stepmother, and more importantly how to distinguish the two from a single sentence. Having read down the thread I'm with Hens903971 on this. Its fine to put this as part of a general discussion as there will be pointers, but a single sentence with no supporting text is a bit of a stretch.
Only context can clarify the difference.
Every language has words which only become clear through context. The point is that, to avoid ambiguity in such instances, you have to be careful that the context makes it clear what you're talking about. That's what parentheses and brackets are for.
Some guidelines for determining relationships in English:
First you ask whether a "step" relationship exists. Step-relationships only arise when a parent marries a 2nd (or more) time and the new spouse already has children with someone else. People thus only have step-fathers, step-mothers, step-brothers, and step-sisters. Everyone has to be alive at the time of the 2nd (or more) marriage. The most important thing to observe is that the "step" relationship only arises if there are existing children of either spouse involved.
Step-relatives are not related by blood (they don't share genetic markers). Sometimes the "step" label is applied to other members of one spouses family, but that's just to expand the idea of "family". "Step-cousin" isn't really a relationship, but helps describe how someone fits in an expanded family.
"Step" relations are thus limited to either (a) your new mother and, if any, her existing children, or (b) your new father and if any, his existing children.
In-laws are people who are closely related by blood to either spouse in any marriage (1st, 2nd, 3rd or more) and who don't fit the step-relative group. Your spouse's parents and siblings are the usual in-laws: Mother-in-law, Father-in-law, Brother-in-law, and/or Sister-in-law. (Again, some people extend the reach of this group to include more people in the "family".) In-laws can be born after the marriage - they don't have to be in existence at the time of the marriage. (Example: If your wife's parents have a son after the marriage, the baby is your wife's new brother and thus your new brother-in-law.)
Children born after a 2nd (or more) marriage are half-siblings to living children of either parent. Such children are related "by the half-blood" They share half the genetic material they would with a full-blooded sibling (brothers and sisters born of the 1st marriage, produced by the same two parents). Example: If your father and step-mother have a baby daughter, then that is your half-sister.
There isn't any usual over-lap in these relationships. Step-relatives are not in-laws and not half-relatives, but there are unusual circumstances which can create over-laps. Step-siblings can legally marry, because they are not legally related to each other. That can change the whole relationship matrix.
It IS confusing! First the whole sentence has to be put on the operating table to determine in an anatomical lesson how the relationship is constructed. Then you can determine which version of 'belle mère' is meant. Dissecting family relationships is definitely not my strong point!
In France, you can probably have two or more belles-mères. Wouldn't be exactly legal, and the Catholic church would frown on it. I know a French man who at one point lived in a multi-floor house, with his wife and children on one floor, his mother on another, and his mistress and her children on another.