The ornamental design for a golfinstructionalaid, as shown and described.
FIG. 1 is a perspective view of the golf instructional aid, the broken line showing of the feet of a person, golf club and golf ball are for illustrative purposes only and for no part of the claimed design.
FIG. 2 is a top plan view of the golf instructional aid.
FIG. 3 is a bottom plan view thereof.
FIG. 4 is a front elevational view thereof, the rear view being a mirror image of the front view; and,
FIG. 5 is a right side elevational view thereof, the left side view being a mirror image of the right side view.