Unfortunately I only speak English which as I've gotten older has bothered me slightly as I really admire the liguistic complexity & beauty that many languages possess and I wish that I had taken the time to learn more however, though I only speak English I am able to convince you otherwise with a high degree of confidence.
As a child I started as I assume most voice artists did, in the bedroom whilst in play, action man always had an american accent and too many mis-spent afternoons sat watching australian soap opera's assured that by the time i was 10 I was able to speak with a perfect australian accent and by speak I don't mean the comical and often steriotypical "Pop another shrimp on the barbi" Crocadile Dundee-esque accent but clear and not over the top observing every slight tone, pronounciation and regional difference, the perfect accent is acheived by not adding too much or over hamming.
By the time I was 15 I was the comedian or clown in my circle of friends and would impersonate various comics, movie characters and television commercials, inspration was gained from such influences as Jim Carey, Sacha Baron Cohen, Lee Evans & Robin Williams as well as many iconic characters from small and silver screen such as South Park, Family Guy & Walt Disney to name but a few of the more obvious though my influences are more varied.
One of my biggest inspirations which I can say is probably the same for most Voice Talent was Don LaFontaine and as a result of his movie trailers I trained my voice to a high standard.
I am able to cover many accents which include Asian, Oriental, African (Which I'm very proud of) Jamaican, Irish (which is a tough nut to crack if you really want to get it right), Scottish, Welsh, English which includes every class and regional dialect, French (Though my french requires some polishing as it was maninly derived watching hours of Peter Sellers in the Pink Panther), German, Russian, Eastern European, Australian and NZ, South African (Which I have always been very convincingly good at but since the release of District 9 it has become more recognisable) & last but by no means least American which was my very first and again I am able to cover almost every regional and class variation.
I am also able to cover lifstyle choices, for example I can be the typical Crack Addict (Though I use the term hesitantly and only as an example), the Surf Bum, the Wiseguy, the Hillbilly, I can be camp, educated, tough, sensitive, dashing and eccentric.
The list needless to say is very extensive and hopefully covers whatever you need, the one man Voice 123, dare I suggest such a thing?