It's been our experience that grammar, parts of speech, sentence construction and the like are simply skimmed over, if taught at all. DD16 had serious gaps in this area because she had not been taught.

Benchmarks begin in 4th grade, are (allegedly) reexamined again in 7th, and by 8th one is supposed to have a handle on this material. But it's not happening. You cannot believe the level of some of the senior essays I have read, from A students. It's frightening.