In Welsh, when you have several words joined together for a noun, the yr goes before the last one, and applies to the whole thing.
In this case, "Mae swyddfa'r heddlu" - the 'r applies to the whole police station.
I remember it because we do the same in English: "the cat's bowl" rather than the "the cat's the bowl" (which means something different).
Similarly: "the police's office" rather than "the police's the office", but sometimes we, like always in Welsh, omit the 's, so we get "the police office" rather than "the police the office".
Thank you for this explanation!
I had been racking my brains for months on why the first article vanishes, and I had come to the same conclusion, but without any clear evidence of this in Duolingo's notes.
The 'Countries' unit does show the loss of the article in expressions such as 'the Welsh flag → baner Cymru, but a general rule in terms of "the (noun 1) of the (noun 2)" turns into "(noun 1) of the (noun 2)" is not explicitly mentioned (or maybe I hadn't understood it this way).
The phrase for 'on fire' is ar dân - no 'n/yn required in front of a preposition such as ar.
Is it not common to use the word gorsaf in relation to the police? That would be the literal translation of station wouldn't it?
Yeah, but I don't think I've ever heard someone call it a police office in English (even Grammerly wants me to correct it to 'police officer' because it's so uncommon).
I asked the question because it seemed to me the only reason the Duo team would use the word 'office' instead of 'station' is if they were specifically telling us that swyddfa heddlu is more common/natural in Welsh than gorsaf heddlu, in which case you are better off using the former.
If both are used equally in Welsh - unlike in English - then I really would have expected it to default to the one most useful from an English learners perspective, is all.