"Dw i'n bwyta siocled yma."

Translation: I eat chocolate here.

[crush]

Could this mean "I eat this chocolate" as well?

[silverlight513]

Technically it can but I think you would use hwn instead of yma

[crush]

Sorry, i didn't quite understand, do you mean you would use hwn instead of yma here to mean "this chocolate"?

[silverlight513]

Yeah, sorry. I've updated it now

[KisVorosRoka]

Ok, but why the "yma"?

[crush]

Apparently it also means "here".

[silverlight513]

It's main use is here. You wouldn't really use yma for anything other than here. There may be special cases though