Half-brother or step-brother
I am working on the updated French family lesson. Is there a way to differentiate between a half-brother (a brother who shares one birth parent with you) and a step brother (a brother who is not related to you by blood, but the child of one's step-parent). I have looked but not seen a way of differentiating.
My Robert & Colins English-French/French-English dictionary mentions: "stepbrother = demi-frère" - "beau-frère = brother-in-law" ( my additional comment for beau-frère: this can be either, as JBEsip mentions, the brother of the person you marry, or it can also be the husband of your sister)