Hi KateS675.
If you are consistently scoring near Q50, then you have a great foundation for scoring well above 700 overall; you just have to drive your verbal score higher, and I am sure that you can do so. In fact, non-native speakers often score rather high in verbal, because scoring high in GMAT verbal is more about seeing what you have to see and executing than it is about being skilled in the English language.
While you didn't say what you have been doing to prepare for verbal, I can say that what you need to do going forward is to learn to clearly define why incorrect answers choices are incorrect and correct choices are correct. Yes, learning some more rules and a few foundational concepts and strategies might be helpful, but mostly, you have to learn to use logic to efficiently and effectively analyze the choices you see and arrive at the correct one.
What the above means is that, in addition to working with a good tutor, you'll have to continue to train on your own, in an effective way.
So, whomever you work with should be someone who would:
- help you fill in knowledge gaps.
- work with you to improve and refine the way you go about answering verbal questions of each type.
- show you how to train to develop skill in arriving at correct answers.
Make your score goal happen, and enjoy the game!