I Can't change the interface languge to English!!!
Did you try this?
Settings>Language Learning>I want to learn Spanish>Save changes
I don't actually know which button is 'Save chages', or for that matter what any of the other buttons mean, so I don't know if I have or not.
A big green button, like the "post" button under a comment as you write it, that says "Save changes" and lights up green when there is anything to save. Hope that helps!
In case you didn't notice, the button in question only says "Save changes" when the user interface is in English.
I was having trouble because the user interface Wasn't in English, it was in a language that I don't speak, (Catalan, I think).
Although It would have been nice to know about it turning green when there's something to save.