An easy way to make an increase in your knitting is to yarn over. This does, however, create a hole in your work. For this reason, it is primarily used as an increase in lace knitting and other pieces where open space is intentional or decorative.
To complete a yarn over, simply bring the yarn to the opposite side of the work that it had been on (from back to front or from front to back) and then continue your row as indicated. By bring the yarn to the opposite side of the work, you are causing an extra length of yarn to lie across the needle when you complete the next stitch. The example shows a yarn over in stockinette stitch on a knit row.
First, bring the yarn forward.
Work the next stitch with the yarn in front: this will involve crossing over the top of the needle to complete the knit stitch. Here is yarn over between two knit stitches.
The single yarn over will leave a hole in your work, as you will see a few rows later.
To work a yarn over increase at the beginning of a knit row, bring your yarn to the front of your work and knit the first stitch of the row. To knit that first stitch, you move the yarn from the front to the back over the top of the right needle tip while it is inserted into the first stitch. This will create an extra loop of yarn that, on the next row, you can knit normally in pattern.
To work a yarn over increase at the beginning of a purl row, bring your yarn to the back of your work and purl the first stitch of the row. You will bring the yarn from the back to the front over the right needle to purl this first stitch. This will create an extra loop of yarn that, on the next row, you can knit normally in pattern.
Some lace patterns call for a double yarn over increase (yo2). Once you have brought the yarn around the needle for a single yarn over, wrap the yarn around the needle a second time. When you work the next row, work each of the two loops left by the yo2 in pattern. Be careful – it’s easy to miss one of the loops, and then you will be left with too few stitches and a large hole in your work.