The purl stitch is worked in the opposite way to the knit stitch and it always begins with the working yarn being held at the front of the work.
In this demonstration I am working the purl row following a knit row. When you alternate between a knit row and a purl row this is known as Stockinette Stitch.
1. With the working yarn held at the front of the work, take the right hand needle and insert it, from right to left, through the front leg of the first stitch on the left hand needle
2. Bring the yarn over the tip of the right hand hand needle, wrapping it from right to left