There's of course no absolute answer as to what makes a "good" or "bad" translation. In some sense, a good translation is one that can be done to the available budget whilst fulfilling its purpose.
However, there are occasions when text quality is the prevailing factor: a well written, readily understandable text will save your colleagues time and leave your clients and business partners with a positive impression. Here are some things that I suggest looking out for when evaluating the quality of a text that has been translated into English. They are the types of criteria that a good translator should be considering when translating your text, and highlight some of the problems frequently encountered in mediocre translations. Some of these points will of course apply more generally to translations between various languages:
- Does the translation overuse formal or scientific-sounding vocabulary? The words that in English sound overly scientific may often be direct translations of words in other languages that are plainer sounding. For example, is the word "anomaly" used when "fault" would sound more natural? Does the translation mention a "pulmonary disease" when "lung disease" would sound more natural to a general audience? These are classic symptoms of a translation from a language such as French or Spanish, where the 'Latinate' word is a naturally derived, normal-sounding word in these languages, but in English becomes a scientific term suitable only for highly specialist audiences.
- Does the translation use words that are understandable, but not quite 'le mot juste'? Does the text talk about "social insertion" when "social integration" would sound more natural? Does it talk about "eventual problems" instead of "potential issues"? Or a person's "administrative situation" when "administrative status" would more usual?
- Are adjectives or descriptive phrases used where English would more naturally use a compound? For example, English allows a phrase such as "remotely-accessible device", whereas other languages may have to use a phrase that literally means "device that is accessible remotely" or "device that allows remote access".
- Similarly, are phrases with "of" or "for" over-used where English would use a compound. Over-use of phrases such as "strategy of/for sales" rather than "sales strategy" are classic signs of a translation from various languages.
- Are determiners ("the", "a", "your"...) used as they would be in idiomatic English? Phrases such as "saw an increased productivity" rather than simply "saw increased productivity" suggest an overly literal translation. More subtly, a phrase such as "the terms and the conditions", "the towns and the cities" rather than "the terms and conditions", "the towns and cities" suggests a translation from a which doesn't usually allow two nouns to share the same word for "the" (such as French), whereas repeating the word "the" is unnatural in English.
- Does the translation use a narrative style and rhetoric that sounds natural in English? We've all seen French museum signs telling us, for example, that "the king will die in 1483". More subtle signs of a translation include the over-use rhetorical questions (which, for example, appear more common in Spanish than English, where they can make your text sound overly childish). In a translation into English, decisions must also be made about, say, the use of contractions ("don't", "can't" vs "do not", "cannot") or preposition stranding ("Who... to?" vs "To who(m)...?") which may not have been issues in the source language. Does the style adopted convey the impression that you want to give to your audience?
Ultimately, the translated text should ideally sound as though it was the original, written to convey your message with the style and readability you intended