I also have difficulty distinguishing ff and th, even though I'm a native English speaker :/
Maybe this'll help, diolch!
EDIT: I just realised I made an error. I meant th, not dd.
I know, but I still have difficulty with them for some reason.
even though I'm a native English speaker :/
Are ambell waith and weithiau synonyms? Or are they used in different constructions?
Both are used for 'sometimes' and 'occasionally'. A matter of personal preference, really. Perhaps ambell waith is the more occasional of the two, but there are probably better ways of making the distinction in meaning if you need to.
in the question I answered last, "At times" was an accepted answer to this. Now it's not. Is there a subtle difference I have missed?
'At times' seems to be an accepted answer still. The usual translation is 'occasionally'.