Fun post! I would speculate that there is no specific link between one's ability to answer Verbal questions in a 2nd language and one's writing ability in a native language.

The GMAT is hard enough for native speakers who intuitively grasp idioms, English grammar and rhetoric. If you have to take a hard Verbal test in Swahili and are having difficulty, the main issue is probably not that you are bad at Verbal, but that you don't speak Swahili!

That said, there are theories that people are "left-brained" and "right-brained" so if you are naturally inclined towards Quant anyway, the GMAT Verbal might pose extra challenges.

Interesting question. It probably depends on one's learning style. I can use 3 languages confidently and yet entirely failed to pick up 2 others while living in cities where they were used widely (for 5 years each!)

So being good at one language doesn't necessarily make one good at all others. Or may be I'm just slow

In my case (I´m chilean)i have studied from some books so far, but still verbal is my weakness. I think that it would be very useful if someone post somekind of a guide for foreign english speakers. Or even better some Gmat Books dedicated to this issue.
Do I have to say that I use to be very good at verbal in my native language??

MM_Ed,

You have a point--a lot depends on one's own native language. I used to think I was great at languages until I realized it was because the ones I've come across before were all Indo-European--because my grandmother's language from the Finnic family seemed mind-boggingly complicated.

Fernando,

For the same reason as above, I don't there can be a one-size-fits-all GMAT guide for non-English speakers. For example, as a Romance speaker you would find definite and indefinite articles (the/el(a) vs a(n)/un(a)) intuitive--an area in which a Slavic speaker would struggle; while things that are intuitive for both would be challenging for Sino-Tibetan speakers.