Suggestion: Endless Mode
I think it would be fun to have a practice mode that has no end. It would just be phrase after phrase endlessly until you decide to end the session. Also, having stats on my performance during the session would be neat to see.
I would like this, especially if the phrases were pulled from all over the tree. When I go into a skill, I think, "I am doing 'politics', that means all the phrases apply to 'politics'." But if it were phrases pulled from everywhere, I think I would learn them better. I know the test that costs 25 Lingots pulls phrases from everywhere, and so I like taking that. But even that has an end. Also, the test doesn't tell you what mistakes you made, only that you made them. I think both (the existing test, and the endless feature) need to tell you, "You missed the following phrases:" (which wouldn't be that complicated to program) or even better "You missed the following phrases, and here are the skills where they are found:"
I'm lazy right now, so I'm afraid you will have to translate my explanation:
"Greetings" se traduce usualmente como "saludos" y es algo común que un texto en español se desee un saludo al final del mismo.
..."le agradezco por todo su apoyo. Saludos."
Puede que no sea correcto en inglés, así que solo es una traducción literal