To snap polylines or polygons to the nearest vertex while drawing:

1. Click Home | Insert | Polygon/Polyline
2. Click on the Plot where you would like the start of the line
3. Hold SHIFT down on your keyboard and click to draw the next point. It snaps to the closest vertex.
4. Continue holding SHIFT down while drawing to keep snapping
5. When finished drawing, press ESC on your keyboard to exit drawing mode.

Updated Nov 8, 2021