I think you have to practice by yourself go on to as much nice books as you can just try to improve grammar and vocabulary i hope you will be improve very soon.

Well, this is my best section because I have an English degree and have spent almost 20 years as a professional communicator. My advice would be to review the grammar basics. Most study books tell you what kind of errors SC questions are trying to test (e.g., subject/verb agreement, idioms, etc.). Learn that list.

Even with my experience, I still get tripped up once in a while if I don't fully dissect each sentence. Always start by determining what kind of error you need to fix (always, always, always!!!). After reviewing the 5 answer choices, you should be able to tell. Also, they LOVE to throw in superfluous preposotional phrases and you can usually ignore those to get at the core of the sentence. Those are there to intentionally throw you off track.

I've also noticed that in most questions, typically 3 of the choices are quite obviously wrong. Just by reading them, you can see the awkward structure or language. Many times it comes down to 2 answer choices that are excrutiatingly close, but at least you have a 50-50% chance at that point.

The other thing I'll say is be careful not to rely on what you think you know (the way you talk everyday) because SC questions are typically testing the good old fashioned rules of English (snore!). The more questions you do, the more you should be able to see what you need to solve for in each question. I do think practicing and reviewing grammar rules are the two best strategies.

Good luck!

Hi Engin,
My situation is identical to yours. I was faring mostly with a 60 %. Then I decided to do each chapter of the Manhattan SC guide coupled with the OG 10 questions for that chapter(the Manhattan guide has the oG 10 Q's pertaining to that chapter). It's been just 2 days since I tried this and have found that my hit rate has gone up to 66 %. I just wish I did this earlier in the prep as I have just about 12 days left for my test. Anyways I am glad that I found a way to increase my SC at least now. I plan to make the most of it for the next 10 days. I hope this helps.

Get a grammar book that can help you master the core grammar rules. I'm generally pretty solid on SC but I got Grammar Smart, and it's a pretty good guide.