I found diagramming extremely helpful. It taught me the relationships between various parts of speech. It also taught me things like how to balance clauses. Through a mechanical look at sentence construction, I was able to grasp basic concepts of 'style' like parallelism, choosing where to place the semantic weight in a clause, etc
That was in Year 7 English
Then Year 11 linguistics we learnt terms like assonance, phonology, phonetics, register etc and that also made my understanding of language better
But even in year 2 English I remember learning phonics - ie how to spell
I think these days there is a reluctance to boil language teaching down to nuts and bolts and it's a real shame b/c nuts and bolts are where style comes from - you can't have fair and creativity in your writing without mastering the basics of parts of speech, subject-verb agreement, clause construction, sentence weighting, and so on