Welcome to the third installment of the Jerry cardigan knitalong, in which I describe the bizarre shapes of these pieces and how they all fit together!
The Front pieces are the most complicated to knit, with a lot of increases and decreases happening at once: armhole shaping, v-neck shaping, and shawl-collar increases at 4 different points. (Luckily, the buttonhole rows on the Right Front are completed by the time you start shaping the upper body.) The shawl collar and buttonbands are all one piece with the Fronts, with a facing that's folded over and stitched down on the wrong side so that the collar and bands are double-layer fabric. This construction combines with the collar shaping to create a Front piece that looks like this:
The shoulder slope and seams are also atypical for a handknit sweater, because all the shoulder shaping is done on the Back piece. This construction hangs nicely on all sorts of shoulder shapes. It's also a detail that's common in ready-to-wear sweaters -- because shaping and short rows are time-consuming, you'll frequently see machine-knit sweaters that displace all of the shoulder shaping to the back piece in order to knit the front piece(s) more quickly.
The sleeves are regular old set-in sleeves with a shallow cap. Sewing them in is a bit unusual, because you can't use the shoulder seam to mark the center of anything (as it's displaced onto the Back, as shown above). I'll share a quick photo tutorial in the Finishing post.