For this crochet cardigan pattern, you need to know how to crochet the houndstooth stitch, the half double crochet in the back loop stitch, and the double crochet cable.
The crochet houndstooth stitch combines crocheting single and double crochet stitches. Each row of alternating single crochet stitch and the double crochet stitch is balanced on the following row by working singles into the top of the doubles and doubles into the top of the singles.
The half double crochet in back loop stitch it’s the easiest stitch you can use as ribbing and besides being very easy to crochet it looks beautiful and add texture to the overall patterning.

The final dimensions of the Harmony crochet long cardigan: are 47 cm/ 18.5 inches in width (94 cm/ 37 inches circumference) and 53 cm/ 20.8 inches long.

The pattern uses US crochet terminology.