Knots

You should produce the knot in the knit stitch row (the front of the stocking stitch). Knit up to the start of the knot. Then knit two stitches (in knit stitch), turn the knitting round and knit the same stitches again (in purl stitch), turn the knitting back again, and knit them again (in knit stitch). So those two stitches have been knitted in three rows, while the other stitches in the row have only been knitted once. This produces the knot effect.

The knot only appears on one side of the knitting.