So why only "prayer" and not "prayers"? I know as a whole concept it's singular but surely there are multiple prayers in a prayer set too.
This has come up before, and according to the minister whom I asked at the time, 'to lead prayer' is apparently the usual expression.
Because of a mistake in the course database, now corrected. They should both be 'leading prayer' in our example:
- gweddi (gweddïau) - prayer (prayers)