That tense is used in Spanish, but only when the action is happening. The pharse given by Duo can be said in Spanish as:
- Hoy como con el juez: I eat with...
- Hoy voy a comer con el juez: I am going to eat...
- Hoy comeré con el juez: I'll eat...
If I say: "Hoy, estoy comiendo con el juez" is a different sentence, in the precedent sentences I was talking about an action that it is going to happen in a near future. In the last one I'm talking about an action that is happening in the present.
The issue here is that Duo has a tense for tense convention. It is the method that Duo uses to control the tense it wants to drill. In other languages which don't have progressive tenses like French or German, the English progressive is encouraged as a translation for the present as the progressive is essentially the default present tense for Action verbs in English. Spanish uses its progressive tenses much less frequently and only to emphasize that the action is taking place at the moment. But the only way to signal that they want to drill the Spanish progressive is to use the English progressive. There are a few cases on Duo where they have had to ignore the convention because it became too awkward, but that is what's going on.
Other places on this site, though, as well as most dictionaries, say that the English present progressive indicative is translatable as the Spanish present indicative, and vice versa.
For instance, the sentences "Tomo vino" and "Bebo vino" can be translated as "I drink wine" or as "I'm drinking wine" depending on context, just as "Como el pan" can be translated as "I eat the bread" or as "I'm eating the bread." As they are here, the first example should translate as "I drink wine," while the second should translate as "I'm eating the bread."
This sentence is Today I eat with the judge. This is most likely going to happen later today. It could be happening right now too. This tense is sometimes used in that manner, but it doesn't have to mean that nor does it literally translate to that.
There is a way to say “I am eating with the judge" if the speaker chooses to be that specific. In context, this could be used in some circumstances when an English speaker would be more inclined to use present progressive, but without context, it is safer to translate what is said, as this totally makes sense as spoken without adding additional interpretation.
I looked up 'spanish personal a' on google (before I didn't even know what it meant) and apparently it is not used for 'indefinite people' because it doesn't matter in this case who the judge was, it could be any judge. So while I'm not sure if this is correct, it seems reasonable.
I answered "Today I am eating with the judge" because it seems to me that would, in most contexts, be the correct translation. My answer was considered correct. Perhaps the contraction "I'm" is what caused BillOen's translation to be rejected, or perhaps in the alternative feedback is working ?!?
That is exactly what you are learning. Luckily Spanish spelling and pronunciation is extremely consistent. If you understand how to pronounce Spanish sounds, you will find that there are only a few cases where it would even be possible to spell a word a different way. That makes Spanish a great language to reinforce your vocabulary by writing it.