“Black hair is what Megan has”? What function does the relative construction serve here? Could you not say “Mae gan Megan wallt du” or “Mae gwallt du gyda Megan”?
Both of your suggestions are correct for the basic sentence.
The construction of this sentence emphasises the 'black hair' rather than any other colour.
eg, Gwallt coch sy gan Megan? Nage, gwallt du sy gan Megan.
Megan has ginger hair? No, she has black hair.
Literally 'Megan has ginger hair doesn't she? No. it's black hair that she has.
I tried 'Megan does have black hair' which I think emphasises it English but this was not accepted. Should it have been?
The unemphatic sentence is, as you know:
Mae gwallt du gan Megan "Megan has black hair"
If you want to emphasise the subject of a sentence with mae, then put the subject to the front and use sy instead of mae:
Gwallt du sy gan Megan "Megan has black hair"
You can do this with other similar sentences:
Mae'r plant yn yr ysgol "The kids are in school"
Y plant sy yn yr ysgol "The kids are in school"
Mae hi'n hoffi dringo "She likes climbing"
Hi sy'n hoffi dringo "She likes climbing"
Mae pen tost 'da fe "He's got a headache" (lit. "A headache is with him")
Pen tost sy 'da fe "He's got a headache" (lit. "A headache is with him")
Was this in the notes? I feel this is the first I've encountered it. I've never seen it before and not in the notes.
I've no idea what's in the notes, sorry. I just comment when people ask questions!
It’s in the notes for the lesson “Emphasise1”. Did you get this sentence during another lesson?
On this note, do you always use 'gan' when referring to a specific person? So it wouldn't be 'Mae ganni/gynni Megan' or 'Mae...gynni Megan', only when gynni is acompanied by hi??
In which case, would you use 'gynnon/gannon' or only with ni?
You only change gan when it comes before a personal pronoun:
Gwallt du sy gan Megan "Megan's got black hair"
Gwallt du sy gynni hi "She's got black hair"
Mae gwallt coch gan Glyn "Glyn has red hair"
Mae gwallt coch gynno fo "He has red hair"
Mae gan y plant a fi wallt brown "The kids and I have got brown hair"
Mae gynnon ni i gyd wallt brown "We've all got brown hair"
Ah, diolch yn llawer am hynny! That's quite different to other languages, so that was probably where my confusion came from.
It is different to a lot of other languages, yes. You also see the same thing at play with verbs:
Cerddodd hi "She ran"
Cerddon nhw "They ran"
Cerddodd y plant "The kids ran"
Mae e'n talu "He's paying"
Maen nhw'n talu "They're paying"
Mae Siân a Siôn yn talu "Siân and Siôn are paying"
You'd never have the verb agree with "y plant" and "Siân a Siôn", even though they're plural. The verbs are just found in their neutral form.
The Syntax of Welsh says "Agreement in Welsh operates only between a head and a personal pronoun, never between a head and a lexical phrase" and goes on to explain that it's something Welsh has in common with other Celtic languages.
@mizinamo can't reply to your comment directly for some reason, but you're right. I hadn't thought of that before. I think it was because I was thinking of 'gen/gan' as a conjugation in itself, as opposed to a preposition.