why is it "à la sortie de" is used instead of "au bord de" ? Would help if these things were explained in the lessons rather than just corrected.

Question

Accepted Answer

Bonjour James,
Chris is right. It isn't really used like that but it is correct.
'au bord d'un lac / d'une rivière' = by the lake / river 
'au bord de la falaise' = at the cliff's edge
vs 
'à la sortie du village' = at the edge of the village
I hope this is helpful.
Bonne journée !

Answer

The "edge of the village" is often (idiomatically) referred to as "the exit of the village", la sortie du village. There isn't anything wrong with au bord du village, I'm just not sure that it is the main phrase used in that context.