"You are eating supper."

Translation: Jecie kolację.

[Cosmopoiesis]

Thanks for neither specifying plural or singular nor which word for supper you were looking for. I was wrong on both counts.

[Jellei]

Without context, both singular and plural (jesz and jecie) need to be accepted, but about supper, I think it only translates to kolacja (the last of the three most important meals), it is obiad which has the neverstopping lunch/dinner debate.

What was your version?

[RiflemanReedy]

So how do Polish speakers know whether the person means lunch or dinner when they say obiad? Or does the speaker have to indicate which meal they're talking about before?

[Jellei]

That's the case, for Polish people everything is obvious. It's English that is confusing ;) At least across dialects.

If you consider the tree 'main meals' of the day, obiad is the second one and kolacja the third one.

[RiflemanReedy]

Ahhh, so it's the translation from Polish to English that's creating the confusion? That makes sense, yet another great thing about learning a language like Polish!