"Rhaid defnyddio 'r gair iawn."

Translation: The correct word must be used.

[gittih]

when the sentence is said, the voice says something like "collnod" before "gair" this is very confusing

[EllisVaughan]

Yes it's because the "'r" has not been stuck onto the end of "defnyddio" here and so the system is reading it as "collnod er" (in English: "apostrophe r").

[sally281539]

Yes, this audio needs fixing!