Is the opposite of Guy, Gal?
..like "moço" and "moça"?
So that expression: "Hi guys!" doesn't work if you're talking to girls..
Yes it works. For old women you must say "Ladies","Women" and even "Girls", Though. They'll be so happy because you're calling them young girls by saying"girls".
Back to the topic about "guys", I mean about the word "guys" ^^. "Guys" can be used to talk about girl groups. They'll not mad at you. I already saw girls talking to each other using this expression. Btw, There's a class of a funny Canadian which you can check by clicking on this beautiful and wonderful button
Adding on, CC for substitles ^^
I hoped I helped you
Gal is a informal way to say girl or woman....
Well, I googled the image, Then I put it in this structure
[![duo](Url_image)](Any link you want)]
Finally, I learned how to type in yellow and I wanna thank Mr.Mello for telling me how to do it.