"Have you gone to work?"
Translation:Dych chi wedi mynd i'r gwaith?
Well, you could, but you would perhaps be more likely to phrase that as "I've gone there to work" - Dw i wedi mynd yno i weithio - or similar.
It is a common problem in something like Duolingo where the phrases appear with no conversational context. In the wild, there will very probably be a conversation of some sort going on which puts a phrase in context, so the potential ambiguities are far fewer.
Yes; it's one of the form of the word for "the" -- so the sentence is literally something like "are you after going to the work?".
The Welsh for "the" can look like yr or like y or like 'r depending on what comes before and after it. Here it's 'r because there's a vowel before it.