What is the singular of 'malwod'?
Malwoden is what I'd use, as so many animals and nouns that are singular in Cymraeg end in -en, but Ellis' "malwen" is also correct.
I have't done the imperfect lessons yet but it is showing that I have. Is there any way of going back?
Yes, just click on any round symbol to look at that unit if you have already done it.