Scores seen a sudden drop

See my post here https://gmatclub.com/forum/700-with-terrible-split-181043.html#p1406872. This method worked especially well for me in verbal.

Hi rom12,

GMAT exams generally range + or - 30 points from your average practice exams. Everything from stress, to what questions you answered can have a toll on this. Certain questions hold a different weight than others, as getting two questions wrong can sometimes affect your score in the same way getting one wrong can. Although there usually isn't that big of a range, sometimes it happens. Without knowing major specifics of the 3 exams, I cannot say what specifically happened with the last one.

With that being said, your main question was in regards to Verbal...you have realized Verbal is an area of weakness. Knowing what your weaknesses are is key to GMAT preparation! First, do not rush to take the exam...if you think you are ready go for it, but if possible for you to extend it by another month, I would say do it. The extra time would be great for you to work on the Verbal. You should start by going back to the basics. Without knowing the basics of grammar you will have problems with all verbal. Even if you know the majority of the basics, there are most likely a few basics you don't have down. Get yourself a book that covers grammar basics. After you feel that you have this down, then I would recommend taking a practice test or some practice verbal work to determine your specific areas of weakness, and focus on those sections. Do not move on until you have them down. After you feel more comfortable with these sections I would then go back to working on overall practice questions for verbal as a whole. If you feel you need more grammar practice we would recommend "English Grammar in Use" (intermediate and advanced levels). Please be aware that almost all grammar books tend to be exercise-oriented and often go into much more detail than what the GMAT tests. In addition, many grammar books do not deal with certain sentence structure issues (e.g. dangling modifiers). You need to cross-reference what is on the GMAT with the book you get. But "Grammar in Use" is probably the best grammar self-study book available.

If you have problems determining your areas of weakness and if you extend your test date, I would recommend getting a good adaptive course that will determine them for you. If you decide to go this route, check out https://gmat.economist.com/ for a free trial with an adaptive course.

If you have any other questions at any point please feel free to ask, I hope this helped a bit.
Good Luck!
-Evan