Is 'chwe' a regional thing? If not, are there certain situations where the 'ch' is lost?
I'm a native English speaker too, and I've never heard anyone use "of" to tell the time. It's less colloquial, more like obscure. In any case, the creators of this course (mostly) accept colloquial language, both English and Welsh, so long as it's not too obscure. If you often hear that way of telling the time, then fair enough if you report it as an un-accepted correct answer.
do you apriximate the time in welsh, or is it always exact? for example, in english for six minutes to eight you would usually say "its nearly 5 to 8"?
in my experience, it's much the same as in English. At 7:54, I'd say it's "pum munud i wyth", unless someone asked for the exact time.
The voice pronounces "i wyth" as something like "ee oyth." Is that error or just natural pronunciation flow after "i?"
I wrote mae'n chwe munud i wyth , but I got a 'wrong' notice.
I think mae'n... has not been added among the correct answers.