You could but if you knew the context in this case it would not be necessary. This particular example could mean: Is he walking or running there? or Are You walking or running there? "You" is supposed to show that it is formal. Sometimes I feel that a picture would help the student decide what the situation is. Hope I helped.
You help greatly. There's a lot of learn about Hungarian. :D
Translating from English to Hungarian is a bit daunting anyway, since for one particular verb you can end up with eight different translations in the worst case (you singular/plural, informal/formal, indefinite/definite). And, like in this case, four in the other direction (he/she/it, and you). So, patience while this course is built up and use the report function wherever needed. :)