Okay, G minor. We're going to take an E shape, E minor, and we're gonna move that to the third fret. All right? Here's my bar at the third; here's what looks like an E minor chord. I'm strumming all the strings, and that's G minor.
Then of course I could do that with the A shape. So, I'm taking A minor, because we want a G minor chord, right? So I have to use it in a minor shape. I'm just adjusting my fingers so I have the first one free. I bring that to the 10th fret, that's where G is. So here's G minor.
That's how you make a G minor barre chord.