The squarey sweater is made with four granny squares for the front and four for the back, then joining with a continuous join, shaping the shoulders and adding some sleeves.

Materials
Dk / weight 3 yarn. For my example I used Stylecraft special dk
3.5mm and 4.5mm crochet hooks

Written in English US terms with abbreviations for UK

The PDF is 25 pages with plenty of photos and a helpful video to join the squares.