Just as in Photography, where the Automatic Mode does not offer enough choices to be creative to demanding photographers, a bilingual with little education may lack the skills to translate with style.
How important is style? Some translations are hopeless from the start. Often these are a result of translation software, or are the work of native speakers struggling with a grammar book in one hand and a dictionary in the other. These are good for a laugh. Other translations are technically accurate, yet the sentences do not flow as smoothly as they should; word order or choice of vocabulary may be unduly influenced by the original language and by ignorance.
Education Matters. If you ask five people to write up a 100-word product description, you will get five texts; some clearer and more readable than others, but undoubtedly those familiar with the subject will produce a better text. Thus, the more technical your subject, the more important it is that your translator knows it inside-out rather than learning the subject at your expense, or even worse, making up terms.
Beware, bilinguals may speak both languages fluently, but they may not necessarily be good at moving information between languages, especially in writing. Many bilinguals overestimate their communication skills and lack formal training that can only be acquired through a college education.
Professional translators are effective bridges between languages. They produce texts that read well because they use the appropriate grammar, syntax, punctuation, style, and terminology of the target language.
Good translators are inquisitive. They strip down the sentences entirely before creating new ones in the target language. Furthermore, they ask questions along the way. Good translators build solid relationships with the author. Good translators are proud to sign their work.
B.A. Foreign Languages, French and Spanish, cum laude