"Megan sy 'ma."
Translation:It's Megan here.
I don't understand why 'It is Megan who is here' is not accepted here. In a previous sentence the translation for Owen sy 'na was given as it is Owen who is there. So is it the 'ma and 'na here that make the difference or is this a DL error. I have requested my answer be accepted.
That's possible, yeah. Anyone could use either really. Mae Megan yma is the normal, neutral "Megan is here" with no special emphasis whereas Megan sy 'ma is "Megan is here" with emphasis on Megan i.e. "Megan is here (as opposed to someone else / not somebody else)". That's why, as you say, Megan might say Megan sy 'ma when answering the phone, for instance.
someone else would observe 'Mae Megan yma' I think...
Well, unless they want to say Megan sy yma.
For example, a visitor to your home hears a voice from another room and guesses that it's your next-door neighbour Gwenllian, and you correct them with Megan sy 'ma "it's Megan who's here (and not Gwenllian)".