Struggling with SC and CR

If you've read and understood the MPrep SC Strategy Guide, then you know all of the grammar you need to do an excellent job on SC. The fact that you aren't doing an excellent job on SC, suggests that something like this is happening:

- You don't remember or understand some/all of the SC grammar info - possibly due to studying poorly;
- You know the 'rules', but you don't know how to apply them on problems, or you're applying them incorrectly or in the wrong situations;
- Your SC strategy is weak - you aren't reading carefully enough or noticing the right things, or maybe you aren't starting with the right splits.

Do any of those seem reasonable to you? What you should do next on SC depends on what the real issue is. If you need to learn the grammar more thoroughly, it's going to mean flashcards, writing up your own cheat sheets, and lots of spaced retrieval to make sure you remember everything 100%. If you've learned the rules by heart but you can't apply them, you need to work on how you review the problems that you do, and consider a technique like 'when I see this, do this' (https://www.manhattanprep.com/gre/blog/ ... e-problem/ is a GRE article on the topic that's also relevant on the GMAT.) If you're struggling to do SC problems, you need to learn about strategy, and then go apply it on lots of high-quality SC problems.

Sadly, it's a lot harder to find high-quality 3rd-party problems in Verbal than in Quant, so some of the GMATClub problems you'll find won't be great. I'd recommend spending most of your energy on the Official Guide to the GMAT and the Verbal Review book.