1. On your phone, open Settings.
2. Scroll down to the System option and tap Language & input.
3. In the Language & input window, look for the option Virtual keyboard. Tap it and you will see a list containing the keyboards you have enabled.
4. Select the keyboard for which you want to reset the dictionary. Once you tap the keyboard, you will see the Reset settings option.
5. Tap Reset settings and confirm it. The dictionary for the keyboard will be reset.