Automatically switching language when adding
Anki 1 had a feature (only on Windows machines) where each field would remember the keyboard input mode you've selected. Anki 2 uses a different approach to showing fields, and unfortunately the toolkit doesn't seem to to support automatically switching languages anymore.
It's recommended that you set up Windows so that you can use a simple combination of keys to quickly switch back and forth between other languages. After doing this, you will be able to quickly switch back and forth not only in Anki, but in other programs as well.