Translation:I study Spanish in school.
I agree with the previous comments, you only provide one way of answering questions which could be translated in several ways. It is too limited. I am a Chinese teacher. I am doing the skills just for fun. We never teach language in a limited way, more translation should be accepted.
I think they want to distinguish between the progressive (in English ~ing) from the present. For that reason, the "correct" translation of I am studying Spanish at school" would be: 我正在学校学習西班牙语. But I still think they should accept: "I'm studying Spanish at school" for this question. The important thing is the accuracy of the target language, not the language you're using to study the target language.
At 77, I find that my tongue, vocal chords, brain and other components of my oral communication are not as nimble as they were when I was younger. So Duo's system of allowing repetition of the recorded sentence over and over is ideal for my personal learning. So if I play it 10-20 times each time repeating with Duo's voice, I can say the sentence as fast as Duo. A sentence like this with its repetition of similar tones and sounds is particularly challenging for me
Since English translations of this sentence involving the "-ing form" (pres. prog.) of the verb "to study" are marked as being incorrect, the question becomes: How do you distinguish between "I am studyING spanish at school" and "I study spanish at school" in Chinese?
As far as I know, using "(zheng) zai" before the verb allows for a meaning similar to that of the English present progressive, BUT(!) - if I'm not mistaken - this construction is mainly for "emphasis"(?), and NOT equivalent in meaning to the English present progressive (relative to the English simple present).
Rather, the Chinese "simple verb construction" can in fact(?) be used to convey both meanings. Hence, "Wo zai jia chi fan" could be used to convey BOTH a meaning like "I eat at home [every day, etc]", AND a meaning like "I'm at home eating" (for example, when your friend texts you to ask where the *** you are).
NB! This is how I have understood the Chinese grammar; I am not saying that this is the way it IS. - Hence, it would be really helpful if the Duolingo team would take time to either explain this grammar issue in some detail, and/or fix the translation inconsistencies.