YO is the abbreviation used for yarn over, and is used generically in instructions. There are a couple of ways to work a yarn over. You may find that you want to work the yarn over in front of a knit and purl differently to get the same size stitches.
Yarn Over – before a knit
Bring yarn forward as if to purl then going over the right needle, return yarn to the back of work to work the next stitch.
Yarn Over – before a purl
Bring the yarn backwards between the needles then over the top of the right needle into position to work a purl stitch.
Yarn Over – smaller YO before a purl stitch
Bring yarn over needle to front and purl next stitch using finger to hold yarn on right needle. This makes a smaller opening.
Yarn Over – larger YO before a purl stitch
Bring yarn forward between needles as to purl then going over right needle, bring it forward again and purl the next stitch. This makes a larger opening.
See also: dbl-YO or double yarn over
Pattern Specific Variations to Yarn Over
Sometimes, I include technique variations that are for specific patterns. I always include directions for specific techniques in the pattern itself, so be sure to also read any patterns you’re working on closely.
YO, k2tog-b Variation for Capri Shawl
At the beginning of the row, wrap the yarn for the YO from back to front, then go into the back of the first two stitches on the left needle and k2tog-b. Wrapping the yarn in that direction will help it stay on the right needle while working the k2tog-b.
Drop YO for Assen Gansey and Emmen Gansey
After placing waste yarn through the YOs on the needle, work next row/round as directed, and whenever a YO is encountered on the left needle, drop it off the left needle. It will be held by the waste yarn.