This article explains how to turn off autocorrect (Auto Replace on Samsung phones). It also contains information about other text options in the Auto Replace screen. This information applies to all Samsung smartphones.
How to Disable Auto Correction on a SAMSUNG Device
Autocorrect can be a real lifesaver sometimes, but it can also work against you by changing the meaning of a message. Turning off autocorrect is easy.
From the Home screen, tap Apps > Settings.
Scroll down to the System section and tap Language & input.