How to half double crochet
As the name suggests, the half double crochet (hdc) is half the height of the double crochet. I like to think of this stitch as a hybrid between a single and double crochet. It has a little more height than the single crochet but is tighter than the double crochet.
Begin with a foundation chain, or a row of stitches, of any length. The turning chain length for half double crochets is 2 chains.
To create a half double crochet, yarn over and insert your hook into the third chain from your hook or the next stitch. Yarn over and pull through a loop (you should now have three loops on your hook), then yarn over and pull through all three loops. That’s it!
Check out the video below for a visual on how to half double crochet.