Dear Hiring Manager,
I write to express my interest in this position. As a native Spanish speaker with an impeccable knowledge of grammar, spelling, punctuation and word usage, I can deliver translations which are accurate, natural and credible to a Spanish market, sounding as original pieces of writing and not just translated texts.
I'm available to start work immediately, so I look forward to having the opportunity to go through my application in more detail with you.
Yours faithfully,
Raúl Ranz