Your brother just switched days for washing the dishes with you so you could watch a TV program you like. Use and I-message to tell him how much you appreciate this. Include specifics, feelings, reasons, and needs.
Hey bro, I can do the dishes today, go and watch your TV show.
I feel like I should repay him for what he has done for me lately. Maybe I could go buy him something
Here is your Pixel 2 phone sir!
Oh wow thanks!
Hey, Thanks for helping me lately, and I decided to get you this.
<-- wanna play Minecraft together? Okay, sure! -->