Some people will wonder why I have asked this question. Isn’t it pretty much given that translations should always be done by native speakers translating into their own language?
The orthodox view is that only a native speaker can find just the right expression to convey the sense of the source text and avoid grammatical errors. A case can be made for an alternative approach: only native speakers can be sure of understanding the meaning and associations, cultural and otherwise, of the source text, and translation mistakes are, in my experience, nearly always the result of a misunderstanding of the source.
Suppose you take a good fluent, but not native, speaker of the target language. Any mistakes he or she makes are likely to be stylistic, grammatical and syntactic, all of which will be rather obvious to the native reader. Mistakes made by people translating into their native language are likely to be much more difficult to detect, since they will, we hope, be expressed in correct, stylish language. So we end up, de facto, with a situation in which we tolerate invisible mistakes of accuracy provided there are no visible mistakes of style and grammar. And yet there are certainly cases where accuracy is far more important than a few easy to correct grammatical mistakes.
Another complicating factor is the place of residence. An American linguist living in Shanghai may have a much better grasp of the source Chinese than one living in New York, but may at the same time be out of date regarding the “normal” terminology of current affairs, youth slang, etc. This is especially relevant in the case of cultures which have much less global projection than either Chinese or English, and where linguists living abroad can end up being out of date regarding modern usage in their own language.
I’m not really arguing for a change to the orthodoxy. In fact I believe the best solution is for a native speaker of the source language to collaborate with a native speaker of the target language. In fact some of the best translation partnerships are between members of the same family or household, where each has a different linguistic and cultural background. In QuickSilver we sometimes have a source-native translate the text and then get a target-native to review and correct it, focusing on the style. Sometimes we do it the other way round, with the source-native linguist concentrating on accuracy. Both methods work quite well.
We recently translated a piece from English to Spanish which included the phrase the last straw. The translator did not recognise that this was a reference to the English expression “the last straw which broke the camel’s back”. A native English speaker would at least have realised the intent of the writer, and could easily have known or found out the equivalent Spanish expression “la última gota que colmó el vaso” – the last drop (of water) which made the glass overflow”. Instead, the native Spanish translator rendered it literally as “la última paja”, which has the unfortunate colloquial meaning of “the last wank”!