A good translator is by definition bilingual. The opposite is not
necessarily true, however. A born and bred bilingual will still
need two things to become a tranlator: first, the skills and
experience necessary for translation; second, knowledge of the
field in which he or she will translate. The skills and experience
for translation include the ability to write well in the target
language, the ability to read and understand the source language
material thoroughly, and the ability to work with the latest
word-processing and communication hardware and software.
Does a born and bred bilingual make a better
translator than someone who learned language B later in life? There
is no definite answer, but the following issues are important.
First, a born and bred bilingual often suffers from not truly
knowing any language well enough to translate, with some even
suffering from what is known as a lingualism, a state in which a
person lacks a full, fluent command of any language. Second, born
and bred bilinguals often don't know the culture of the target
language well enough to provide top-quality translations, or can
not recognize what aspects of the source language and its culture
need to be treated with particular care, as they are in a sense too
close to the language. And last, they often lack the analytical
linguistic skills to work through a sticky text.
On the other hand, the acquired bilingual may
not have the same in-depth knowledge of colloquialisms, slang, and
dialect that the born bilingual has. Also, the acquired bilingual
will not be able to translate as readily in both directions (from B
to language A and A to language B). Finally, born bilinguals often
have a greater appreciation of the subtleties and nuances of both
their languages than someone who learns their B language later in
life can ever hope to have.