"She has toothache."
Translation:Mae'r ddannoedd arni hi.
Noooo... just when I thought I'd cracked it! I understood that a particular part / area of the body, the constructions is with "gyda". But a general malaise, such as a cold, temperature etc, it is "arni hi" etc. Teeth are a particular part of the body, so... why? Please.
No, you're right: if a part of the body is mentioned, it's gyda, otherwise ar is used.
Y ddannoedd isn't a part of the body. The parts of the body are dant "tooth" and dannedd "teeth", but we don't say *dant/dannedd tost - we used y ddannoedd.
I know dannedd "teeth" looks similar to y ddannoedd "toothache", but one is a part of the body and the other is a pain, so it takes ar. Initially slightly confusing but the rule still holds.
The question accepts "Mae ganddi hi ddannoedd." but is "Mae'r ddannoedd arni hi." better?