"Nac oes, does dim rhaid i chi fynd."

Translation: No, you do not have to go.

[jenna683537]

'No, you must not go' is incorrect?

[rmcode]

As in English there is a clear difference between 'not having to do' (does dim rhaid) and 'must not do' (rhaid beidio)

[ibisc]

Correct, it is incorrect. As explained in the notes, that would be Rhaid i chi beidio â mynd.

[PeterThoma23562]

What is wrong with ' No, you need not go.'?