You're asking for a quick fix - unfortunately, there really isn't one on verbal. Yes, you can memorize a few grammar rules, but to do well on verbal you need to solidify your foundation in English. The best way to do this is simply to read well written and moderately complex materials (Wall Street Journal, Economist, whatever). This will improve your logical thinking skills (for CR), your eye for good grammar (for SC), and obviously your reading speed and skill (for RC).

Any prep guide will give you some grammatical rules to learn and some basic approaches for the other verbal sections, but - more so than does the math section - the verbal section tests skills that subtly tests skills acquired over a long time.

I've had students make reading 30 minutes per day part of their GMAT prep, to set that verbal foundation - I think that's a great idea and will probably improve your score more than a prep guide could.

Great advise VIP!
In addition to reading the Economist and WSJ, I would highly recommend the MGMAT SC guide.
It is KEY for grammar and sentence construction rules.

Hi,

Can you give any suggestions on which one is better out of MGMAT SC or Powerscore SC bible?

Thanks

I have used many books in my preparation for the GMAT, but the best one I have found so far is the Manhattan GMAT SC. The book will not only teach you correct American written English but what the GMAT folks consider correct English.

My mother is an English professor so, I was somewhat surprised that my SC score was only 90%. In my own opinion I disagree with some of the grammar rules the GMAT folks consider correct; although, they are the ones who make the rules.