T9 mode works only in Portrait mode. So if you’re in Landscape mode, a QWERTY keypad is used with the default set to Abc (text) mode.
As per Samsung Technical Support (LiveChat support), to turn off the predictive text please go to the “Messages Application”. Then click on the mic option you see in the keyboard.
Please click on the “Settings” and you can find the predictive text option or the dictionary option. It's on "green" when the productive text is on. Please disable the option or “turn Off” the toggle. After you turn it off it will be colored "grey".
In latest buzz, Samsung's Galaxy S7 phone may be water resistant, as a Samsung video teases a Galaxy phone being used in the rain and with a wireless charger. Find out more at CNET.