To work a half treble crochet,
1. Start off with your foundation chain and wrap the yarn around the hook.
2. Insert the hook from front to back in the third chain from the hook.
3. Yarn over the hook once more.
4. Pull the yarn through just the chain or first loop on your hook, leaving three loops on your hook.
5. Yarn over the hook one last time.
6. Pull the yarn through all three loops on the hook leaving one loop on the hook. This completes one half treble crochet stitch.
7. Continue along the row working one half treble in each chain stitch.
At the end of the row turn and work 2 chain stitches, these count as your first half treble crochet, miss the first stitch and work a half treble crochet into each stitch made on the previous row, the last stitch gets worked into the top of the turning chain.