Hi Sandor,

The OG11, OG Quant and Verbal Review books are indeed very useful tools for practice and studying. Since you didn't mention your study plan for the Verbal part of the test, I would recommend starting with that section, since it seems that Verbal is your weakest point. When doing Verbal (and Quant) questions, try to review each question and really understand WHY you got the question right or wrong, instead of just glancing quickly at the answer explanations when you're done. Try also to do larger problem sets in one practice session to build up stamina for the actual test! However, keep in mind that the questions go from easiest to hardest in level of difficulty on the OG, so you might want to plan around that accordingly.

While you're focusing more on the Verbal section of the test, don't neglect the Quant part! Keep practicing for that as well; you don't want to lose what you've already learned for that section.

I have seen students increase anywhere up to around 200 points, so don't give up hope. It does depend a large part (if not entirely) on you, though - how much studying you do, your 'talent' for taking the GMAT after you've put in a certain amount of studying, and etc. Going up 140 points definitely isn't easy... and any prep is certainly better than no prep, but I'd recommend looking into a prep course if you have easy access to one (I admit I'm biased but it may help quite a bit). This way you'll get some guidance to help you maybe gain a different perspective on the test, which could help you get the score you need.

Hope this helps, and good luck!