A square is made up of four couples, aligned with the walls of the room.
In each couple, the lady stands to the right of the man.

Your partner is the person next to you facing the same wall.

Your corner is other person next to you - facing a different wall.

The couple with their back to the caller is Couple #1, a HEAD couple (purple).

The couple to the right of couple 1 is Couple #2, a SIDE couple (green).

The couple to the right of couple 2 is Couple #3, a HEAD couple (blue).

The couple to the right of couple 3 is Couple #4, a SIDE couple (red).