Yesterday a yrn (yarn round needle) was required at the start of a purl row, today a yrn is required at the start of a knit row. As they say ‘a picture paints a thousand words’, so if you look at the photo above it shows how to take the yarn around the needle before you start knitting the row.
Thread the yarn from the rear towards you over the right hand needle, then take the thread, which leads to the ball of yarn back to your knitting position, forming a loop over the right hand needle.
Then insert the working (right hand) needle into the next stitch on the left hand needle (as shown above) and continue to knit the stitches in this row as directed in the pattern