Previously, when you are using iOS8, you might accidentally typing lowercase letter when you want an uppercase letter although there is uppercase and lowercase switcher that also act as the indicator. But the new iOS9 provide an instant view by showing its letter either it is a lowercase or uppercase before you start typing (while maintaining all its spaces and layout)
But not everybody able to fit this new feature. Some people still want to stick with the old keyboard layout. So, how to turn off showing lowercase keyboard while typing?
Go to Settings and type “Keyboard” in the Search text box
Choose Keyboard (General -> Accessibility)
There are a lot of keyboard setting available but only choose under the accessibility function
Switch off the Show Lowercase Keys
By default the how Lowercase Keys is turn on (showing the green button). Tap the switcher to turn it off.
Start typing on the old keyboard
You will see the keyboard layout maintain showing uppercase letter as in iOS8.