In grade school, we HAD to diagram sentences and do all the other writing and reading assignments in order to pass to the next grade. Failing a class was VERY much a possibility.
If schools have dropped THIS approach in favor of something ‘kinder’ for students... then they are just putting off the hard work, disappointment and emotional let-down to a later date.
The optimum time to learn these basics is in grade school and it is a tremendous disservice to young people (who ever they are) to pass students without an understanding of this.
Bingo! All over the country, school districts are spending a fortune of our tax money trying to teach high school subjects to students who did not learn in elementary school to read, write, and do arithmetic. There are all sorts of specialists, technology, curriculum creativity, and excuses ... but the problems originated and need to be fixed at the 1st-3rd grade level.
The only real solution would be to have students without basic skills go into classes where they are taught, no matter what age they are. Significantly, we have such classes outside the schools-blob: they're called "adult literacy and numeracy" programs. They're taught by volunteers usually working for private organizations, and the students are there because they have decided they need the skills they don't have.
as a homeschooling momma, i had my oldest son take pre-algebra two years in a row even though he averaged a "C" the first year... i could not see him moving on to something more difficult without having mastered what was basic to the next level...it was one of the best decisions i have made in regards to his schooling... the following year he aced it and has excelled in mathematics since... i know that math is developmental... the first year he was not ready to grasp it at his full potential...