@44m1r, no. In Spanish "el" goes before a week day, however "en" is implied (which would help with the literal translation in english) but you are learning Spanish, not english so the translations/expressions won't always be like for like, nor will they necessarily make sense if translated as such. Hope that helps.
Earlier today i translated this by adding an "s" to sunday, to see if it would be accepted. "Do you work on sundays?" And i got it correct. I just did the same and got it wrong......... Normally when i test out of levels i dont get any wrong. Now i have one wrong and im not getting my gem thingy at the end........
Technically "on Sundays" can only be translated from "los domingos" when it appears in situations like this.
I know how you feel about the gem thingy. It's really a bummer. If you really want the gem you can quit the lesson before it ends and have another go at it.
There is going to be a problem when the English can mean either of 2 meanings. Do you work on Sunday can mean Are you working on Sunday, but usually it means do you work on any Sunday. The better Spanish would be los domingos, but I can see why they keep it easy for us, kind of!