Switch between keyboards when using an external keyboard with iPad
With an external keyboard on iPad, you can switch between the language keyboard for your region, an emoji keyboard, other language keyboards that you add, and the onscreen keyboard.
Switch between language keyboards and the emoji keyboard
To cycle between the language keyboard for your region, the emoji keyboard, and other language keyboards that you add, press and hold the Control key, then press the Space bar.
With Magic Keyboard for iPad and Smart Keyboard, you can also press 
to choose between keyboards. If you want to use to show only the emoji keyboard instead of switching languages, go to Settings 
> General > Keyboard > Hardware Keyboard, then turn on Press for Emoji.
Tip: If you added a Chinese, Korean, Japanese, or Hebrew keyboard, you can press the Caps Lock key to switch back and forth between Latin script and the other keyboard you’re using.
To prevent use of the Caps Lock key for switching languages, go to Settings > General > Keyboard > Hardware Keyboard, then turn off Switch Languages using Caps Lock.
Switch to the onscreen keyboard
Tap 
in the Shortcuts bar (at the bottom of the screen), then tap 
.
To hide the onscreen keyboard, tap 
.