Practice Too Hard!
Why is it that today the Practice sessions contain vocabulary and tenses I haven't learned yet? Up till now Practice was mainly a review, but today I have run out of hearts four times in a row. I don't know Spanish at the level of the questions.
I just got this problem myself. Suddenly I'm doing past tense in Danish despite not even being close to unlocking that skill to learn yet. I am imagining that Duolingo might occasionally throw this kind of curve ball in at you, "on accident on purpose," to see if you're taking it seriously or cheating somehow. Well it just found out I'm taking it seriously, 'cause I quit that practice session.