To make a crochet chain, first make a slip knot and put it on your hook. Follow the link to a tutorial on slip knots if you’re unsure how to make one.
Yarn over (wrap the yarn around the hook from back to front).
Pull the yarn through the loop on the hook. Done!
Build up a number of these by repeat steps 2 and 3 and you can see why it’s called a chain. Each “v” shape is one stitch.
Chains are used to start most flat crochet projects (blankets, scarfs etc.). In amigurumi they’re used for more unusual shapes – open pipes, where the chain has to be joined, or as a decorative belt.
If you prefer to learn through video, check out this tutorial over on Instagram.