Standing up the Hebrew in translation is the same as the Greek. Second nah they see it as one gender and obviously it is two genders period if you can find information as to why they claim it is one gender then you can go and find it I am not willing to do the research for you. You claim it .I show you already the two genders and how they decline. The plural in the text in Matthew is Adelfoi and Aldelfai...
55ουχ ουτος εστιν ο του τεκτονος υιος ουχ η μητηρ αυτου λεγεται μαριαμ και
οι αδελφοι αυτου ιακωβος και ιωσηφ και σιμων και ιουδας 56και
αι αδελφαι αυτου ουχι πασαι προς ημας εισιν ποθεν ουν τουτω ταυτα παντα
Matt. 13 ^
You can see that KJV translates it his brethren and his sisters while in actuality it is :brethren, kinsmen cousins, nephews, uncles, step brothers, brothers and for the adelfai it is the fenimine for the ones above. Yeah they are wrong. I know my language and all and if you cannot see it I cannot do a thing I am sure others can...
the root of the word has to do with the womb but not the same womb.. as "a=delphis" would actually mean the opposite... It also means step brother and half-bother. The usage of Brother int he NT times is NOT used ONLY for the blood relatives so even if it means ALL these meanings it just come to show you that it is not an exclusive name ...But we have gone the Mary-go-around this issue millions or trilliosn of times ....brother Standing Up.