When your bring your personal device into a foreign language classroom, you should be familiar with how to efficiently use it in your language of choice. Below are some tips for switching the default keyboard layout on your devices, as well as some specifics about using different languages within popular district programs.
Mac (OS X Mountain Lion)
Note: The Android platform is fairly fragmented. The steps below are general, and you may need to search the web for directions that apply to your OS version in particular.
Settings -> Language & input -> Android keyboard (tap the settings icon just to the right) -> Input languages. Select as many as you want.
Now, open any app which uses a keyboard, such as Messaging. Pop the keyboard and you will see that the spacebar now indicates the current language setting, for example, "English (US)". Look just to the left of the spacebar for a button with a world map icon. Tap it once to instantly switch to an alternate language (mine is Italiano). If you have just the two languages setup, tapping the world icon will swap between them; if you have than two, it will cycle through them. You can also tap/hold the world map icon for a different method of choosing.