On top of what Jason said, another way you can achieve this is by left clicking their name and a display with several buttons that you can click will appear. There you can mod the person you wish, and also, this can be done by left clicking the person's name in the chat if they spoke.
Hi all, I have a problem. My friend wants to give me moderator rights, but he can't. He writes /mod [my username] and... nothing. I'm not moderator. But if he writes /mods, he can sees me in the list. WTF ? =/
Hey guys for all of you wondering why you can't mod somebody or why somebody cannot mod you well the solution is quite simple, all that person has to do is spell your username perfectly so as an example /mod SKYE_Reki instead of /mod Skye_reki another thing you have to know is that if you want to mod somebody one the Xbox One all you have to do is download the Twitch app and sign in, then proceed to tap your username on the left hand side of the screen then you should see two tabs, Information and Chat. Tap chat and proceed to type /mod [username]. [Username stands for that persons username spelt perfectly