Hi,
To switch between floating and normal keyboard
Go to Settings.
Tap My device tab.
Scroll down to find Accessibility, then tap it.
Scroll down to find Magnification gestures, then slide the ON/OFF switch to the left to disable this option.
Now, go to a screen or an app where you can enter text (e.g: Messaging app, Email app, Browser app, etc).
Tap and hold the key in the left side of the space bar and then select the ''floating keyboard icon'' to switch between normal and floating keyboard.
''If you wish to permanently disable the Floating keyboard you need to permanently turn ON Magnification gestures.''