Yarnicopia

Start off with your row of chain stictches.
You’ll start off like a double crochet by yarning over your needle or crochet hook,
and then you will work into the third stitch from your hook.
Yarn over again
Pull your loop through
Instead of yarning over and pulling through two you will yarn over and pull through all three loops
This is your first half double crochet

Again
Yarn over
Go through the top of your chain stitch
Yarn over again
Pull up a loop

Pull up a loop
Yarn over again and pull through all three loops on your hook
Yarn over go into your chain stitch
Yarn over again and then pull through all three loops

This will be the height between a single crochet and a double crochet.

When you go to turn your row, you chain two for a half double crochet
Turn your work around
Then start the second loop
Yarn over pull through all three loops
(text provided for the hearing impaired)