Visit the Languages @ elementary Weblate to get an overview of the languages supported in elementary OS. If you want to view the support on a per app basis, go to the Projects @ elementary Weblate. If you want to improve the translations, give this Translation Guide a read.
Open terminal and type
$ sudo apt install ibus-avro
Type in terminal sudo im-config and select OK then Yes
Select Ibus as input method for the system
Click Ok and Ok for the next windows. Then restart your computer.
Type in terminal ibus-setup and remember your keyboard shortcut to switch layout, in our case it's Ctrl + Space
Choose Input Method tab and ...