"I live in the big country."
Translation:Dw i'n byw yn y wlad fawr.
In this particular case either can be used. This is common in (feminine) words beginning gwl-, gwr-, gwn- where the -w- is only very lightly pronounced, if at all, by many people. The effect is just a pursing of the lips while saying the /g/ sound, followed immediately by the next consonant.