Step 1: As with the knit stitch, start by holding the needle with the stitches in your left hand and the empty needle in your right. (This tutorial demonstrates the English method of purling.)
Step 2: Pull the working yarn in front of the needles. Insert the tip of the right needle into the front of the first stitch on the left needle, from right to left (Figure 1).
Step 3: With the yarn in front of the needles, travel around the tip of right needle in a counterclockwise movement, passing between the needles from right to left and back around to the front again (Figure 2).
Step 4: Pull the right needle, with the loop of working yarn around it, down and back (moving away from you) through the stitch on the left needle (Figure 3). Slip the old stitch off the left needle and tighten the new stitch on the right needle. You have your first purl stitch.
Repeat this process through the end of the row. When you have purled every stitch on the row, you will have an empty needle in your left hand. Swap needles so that the "full" needle is in your left hand and the empty one in your right, and you're ready to begin the next row.