how old is your brother? if he's younger all you really have to do is tell him to keep his arms open, have a nice relaxed stance, point to where he wants to go let his head and shoulders follow. If he's not afraid of falling and doesn't mind being in a lot of pain... he should be able to connect turns really poorly by the end of the day.
If he's a little bit older then you will need a lot of patience. You might have to unstrap and walk him down the bunny hill, helping him balance so he gets a better feel for how he should balance his weight on the board and how he should twist/transfer weight hips... etc..
I can't teach because I have no patience... also.. lessons can be a waste of time. My first time out, I paid for one of those beginner lifts, rentals and lessons package... the guy took us to the top of the green run and said point to where you're going and move your shoulders... he watched us all do 1 heelside carve and then bolted to the bottom of the hill and waited for us... when we all got down he said, great i'll meet you at the top and we'll do that again... that's how I was taught so that's how I teach my friends, except I don't wait for them at the bottom of the hill lol
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