You know more grammar than you think you do, but it can be overwhelming when people start throwing all of these terms at you.
The thing that you need to do first - and perhaps this will be enough to take you in the direction you really want to go is to start looking for modifiers and prepositions and looking past these. The 3/2 split - or what I call in a more comprehensive manner "decision points" - meaning all of those differences between answer choices where only one can be right and the other is wrong. The 3/2 split is just one type of decision point as these occur when you are down to two or three choices as well.
As I was saying, these decision points are only one strategy for solving sentence correction questions. Getting rid of the unnecessary part of the sentence is another strategy that can really show you that you have much more knowledge of grammar than you thought.
So get very comfortable with prepositions and look past those as they are usually not helpful. Work on identifying prepositions in sentences in your daily life or your other GMAT studies, critical reasoning for example. The other thing to work on getting out of the way is modifiers. I have a technique called "use it or lose it" with modifiers. Basically it comes down to the fact that modifiers can usually only be misplaced. If a modifier is misplaced you "use it" to eliminate the answer choice. If it is not misplaced you "lose it" meaning you read the sentence without it.
If you "slash and burn" as we call it a Veritas and you get some of the clutter out of the way your sentence correction will improve whether you can state the difference between an appositive and and a participle or not.
Here is a post on "use it or lose it"
https://www.beatthegmat.com/unlike-water ... tml#323651
Here are a couple of other posts for you to peruse.
https://www.beatthegmat.com/sentence-cor ... tml#314428
Here is an article as well:
https://www.beatthegmat.com/mba/2011/01/ ... correction
