Mac OS
1. Navigate to System Preferences > Keyboard > Input Sources
2. Click the + icon under the keyboard languages section.
3. Select your desired language and click the Add button.
4. The language should now be available in the Input Menu [US Flag] on the menu bar.
Note: If you want to write in your desired language in more than one application, you have to manually switch for each application (writing in MS Word and then Notepad)
Chrome OS
1. Click on the clock in the lower right corner of the App Shelf to expand the user menu
and then click the Gear icon to open Settings.
2. Scroll to the Device Settings, and select Keyboard.
3. Scroll down and select Change Languages and Input Settings.
4. Expand the Languages section and then click the link to Add a language.
5. Search/ browse for and select the language from the list and click the Add button.
6. Expand the Input methods area and then click the arrow to manage input methods.
7. Scroll down and select
Google Input (for US Keyboard)
8. Lastly, make sure that Show input options on the shelf is enabled.
9. The language will now be available in the Input Menu (US) on the App Shelf, near
the clock.