Hwnnw? Not hwnna?
Either will do.
Could you please add "i mi" as an alternative? It was considered a typo for "i fi". Thank you!
Done. Thank you for letting us know.
would 'ydw i angen dileu hwnna' convey the same idea / still be correct?
That would be more "Do I need to" as opposed to "Do I have to".
Can you use "oes rhaid i mi ddileu 'na" aswell?
When using "That" as a stand-alone, as in not in a phrase "That dog" (Y ci 'na), the "Hwnna/Hwnnw" form is used.