Doesn't need one. In more formal "correct" language it should have a mutation "ddydd Llun" but people don't use it colloquially. Either way, it means "Monday" or "on Monday".
If you were to use the preposition "ar" (on), then it would be "ar ddydd Llun" meaning "on Mondays".
Popping in here to say thanks, Shwmae. I knew about the mutation from SSIW but didn't realize that it's not normally used. I had been wondering about why the difference here.
Croeso. It's taught on most courses but you'll hardly ever hear a first language speaker use it in every day conversation.
That's one thing that people don't get taught much in classes or on courses, the differences in types of speech. That's why it's important to listen, read and get out there and use the language yourself and become your own linguistic detective and tutor. Please feel free to contact me if you have any questions ever. Dw i'n hapus i helpu!
When do I need to know when to translate 'dydd Llun' in a sentence to 'Monday' or 'on Monday'? I've been able to use the former up until this point because the latter was always incorrect...
"Monday" and "on Monday" are still both right. It's probably an oversight. Report it.
Alright, I hadn't reported it because I thought there was a preposition or some phrases which mandated usage of one or another. Thank you.
Technically, "on Monday" is ddydd Llun with a soft mutation. But in practice it's only found in more formal or careful language. Colloquially you'll hear dydd Llun for both "Monday" and "on Monday". (Duolingo seems to be a bit inconsistent in the this regard.)