As we explain in the notes, on this course it is better to translate standalone verb-nouns such as cofio into the form 'remembering' or 'to remember'. This helps to avoid confusion with the command form of verbs such as 'remember!'
Similarly, gwneud on its own should be translated as 'making' or 'to make', to differentiate it from 'make!' or 'a make' (of car, say).
If you look up 'remember' in a dictionary it will show you something like cofio, be, where be is an abbreviation for berfenw ('verb-noun'), which tells you what sort of a word it is. We cannot do that on Duo.
Thank you for your explanation. However, the answer on Duolingo was 'to recall'. To remember was marked wrong.
Sorry, I had misunderstood your point. I have just checked, and 'To remember' and 'Remembering' are definitely in the database as answers as well as 'To recall' and 'Recalling'.