all of these are different ways to say “firefox account”?
Basically yes. The idea is that each suffix represents something that's typically a separate word in English, and you can mix and match suffixes just as you'd mix words.
- my account -> tilini
- to an account -> tilille
- to my account -> tililleni
- to my account too -> tilillenikin
I wonder when Firefox is going to add a configuration menu for keybinds.