This is my 3 year old grandson's figure drawing; - a typical child's figure where he draws what he "knows".
Here in a second drawing are a few more advanced children's figures, with shaped appendages and ideas about hair, eyes, clothing and even eye glasses. Some adults are often stuck with such simple concepts when they first try to draw people. They "know" about bodies, - that there are appendages and body details but haven't either studied anatomy or learned how to look and truly "see". There are some people who without any training or apparent effort at all, draw beautifully. I was not one of those!
Back in art school I had classes in anatomy, lessons about figure proportion and the uses of various media, but truthfully, over the years doing other types of art, I've forgotten most of it! Getting back to drawing the human figure in recent years, I depend on my ability to see edges as line, proportion in shape and the nuances of light and shade.
Most of my figure drawings are simple contour line with added white highlights. These are not quick drawings! I work slowly; looking hard and drawing carefully! I depend on my sight rather than my knowledge.