Not having "you (pl.)" distinguished between "you (sg.)" in the English text is problematic.
I have started using/ assuming you (pl) unless I have a reason otherwise. But I agree, it causes me trouble too
When do you use 'ubi' and when do you use 'unde' ?
ubi -> 'where', current position, no movement.
unde -> 'where from', the former position, movement away.