I felt that my answer should be Italian, as that is the first language I learned, and it is the language of my country. But to me that question actually implies: what language is your main language, what is the language you know best, and in that case my answer would have to be English.

Having moved to the US when I was seven years old, most of my schooling has been in English... not to mention that I majored in English in college and am currently working on an MFA in Creative Writing (in English). The fact that I am an Italian citizen and not an American has also influenced my reading of that question: can I really be a "native" English speaker if I was born in Italy and don't really have "permanent" ties in the US?

When I began focusing more seriously on translation I found that I had a much easier time translating from Italian to English than the other way around. That was around the same time that I moved to Italy for a while and began working with a publishing/documentary production house in Rome. One day I was chatting with one of the Italian translators, who chastised me for being an Italian to English translator, saying that as an Italian I was taking away work from American/English translators. He believed that since Italian was my first language I should only be translating into Italian and not the other way around. That discussion upset me because it both brought out my insecurities with the Italian language and made me wonder whether I could ever be a translator.

Now that I have been successfully translating from Italian to English for some time, I've come to realize that both English and Italian are my "native" languages, and that my level of knowledge of those languages allows me to be a better translator. And who knows, maybe in a couple of years I'll start translating from English to Italian as well!