Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text.
A competent translator shows the following attributes:
• a very good knowledge of the language, written and spoken, from which he is translating (the source language);
• an excellent command of the language into which he is 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;
• 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”.
Sworn/certified translation
For legal and official purposes, evidentiary documents and other official documentation are usually required in the official language(s) of a jurisdiction.
In some countries, it is a requirement for translations of such documents that a translator swear an oath to attest that it is the legal equivalent of the source text. In some cases, the translation is only accepted as a legal equivalent if it is accompanied by the original or a sworn or certified copy of it.