How to yarn over

Yarning over, abbreviated yo, is one of the basic building blocks of most crochet stitches. To create different types of stitches, it may be used before or after the hook is inserted into the piece, or multiple times per stitch.

 
hook in front of yarn

1. Position the hook in front of the yarn.

bring yarn from back to front of hook, over the top of hook

2. Bring the yarn from the back to the front of the hook, over the top of the hook.