"Just two glasses of red wine, please."
Translation:Dim ond dwy lasied o win coch, plîs.
Is gwydraid male or female? How can dau wydraid and dwy wydraid be both correct?
gwydraid, glasiaid and their derivatives are masculine only, according to the GPC and Geiriadur yr Academi.
(However, a few nouns, perhaps some tens in number, can be either masculine or feminine - sometimes as genuine toss-of-a-coin alternatives, sometimes varying by meaning, sometimes by dialect and sometimes having changed as the years have passed. munud is a common example.)
The problem was the multiple choice exercise where I had chosen dau wydraid, but I had to chose dwy wydraid as well.
O.g.y.d is accepted as an answer all in these translations.
The point of this little unit is to show the more informal language you might find in real life, especially in a situation where you're ordering something in a restaurant/pub etc.
Often in these situations 'o.g.y.d. is not used because it sounds a little too formal.