In my experience, "sócio" is only business partner.
"Parceiro" is more like friend, job partner, romantic partner.
What about ,,my partner (masc.)"? Is ,,o meu sócio" allowed here or it means something totally different?
Wouldn't that be a little strange though with the possessive pronoun "my"? Usually we would talk about "our" members in a club. So I don't think "member" would work in this particular phrase with the word "my". All definitions in the hover hints do not work in every sentence or phrase. You have to pick the meaning which has the best fit.
I just wondered if it changes sex whilst meaning the same thing. Nossas sócias (our female members)? Help me Portuguese speakers.
First, only a club, personified, could refer to a member as "my member." One club member could call another one, "my fellow member."
Wiktionary says "member" is also a valid translation: https://en.wiktionary.org/wiki/s%C3%B3cio#Portuguese
"Sócio" can be a member in a club, yes.
But MY member??? That sounds really weird.
Why not? You start a motor club, or a meetup group and everyone who joins then becomes one of your members, especially if you are the president of the club, or owner of the group (pay the bills).
Oficial for business partner, for romantic parnter it's weird....
For common friends, love friends, or wife and husband, use "parceiro/a"
why the "a" is in front? It supposes to translate "to my partner", instead of "my partner", very confusing...
When you have "possessive + noun" the article in opitional. So, minha sócia = a minha sócia = my partner.
To(a) my partner(a minha sócia) = a a minha sócia. A + a = à. So, to my partner = à minha sócia.
Associate or partner (or member in a different phrase), not association