Competent translators show the following attributes:
- a very good knowledge of the language, written and spoken, from which they are translating (the source language);
- an excellent command of the language into which they are translating (the target language);
- familiarity with the subject matter of the text being translated;
- a profound understanding of the etymological and idiomatic correlates between the two languages, including sociolinguistic register when appropriate; and
- a finely tuned sense of when to metaphrase ("translate literally") and when to paraphrase, so as to assure true rather than spurious equivalents between the source- and target-language texts.
A competent translator is not only bilingual but bicultural. A language is not merely a collection of words and of rules of grammar and syntax for generating sentences, but also a vast interconnecting system of connotations and cultural references whose mastery, writes linguist Mario Pei, "comes close to being a lifetime job."
The complexity of the translator's task cannot be overstated; one author suggests that becoming an accomplished translator—after having already acquired a good basic knowledge of both languages and cultures—may require a minimum of ten years' experience. Viewed in this light, it is a serious misconception to assume that a person who has fair fluency in two languages will, by virtue of that fact alone, be consistently competent to translate between them.