BTW, the nuns taught us to speed read (with comprehension tests), do math in our head, and how to write structured sentence/paragraphs/documents. Invaluable skills for my working life...
I remember diagraming sentences in maybe 4th grade. I really liked that.
I taught my kids diagramming in homeschooling. There are some workbooks out there.
I no longer write in my work but I still will occasionally diagram a sentence in my head to make sure it makes the sense I want it to make.