Singleplayer: you cant
Multiplayer: you customize your settings and T is the default button
Chat with our AI personalities
On a Minecraft server, chat is always on. If one of your friends can't chat, then it is a problem on their end.
The deafult key to open the chat is T.
Yes. Go to multiplayer settings > Chat= off.
T by default.
Type "/mute (player name)" in the chat to unmute.