Have you ever been asked to translate a short text or to edit a translation simply because you know how to speak or are a native speaker of that given language? If not, then you will at least have probably heard someone you know mention that a friend corrected a document translated into English because he or she was born in the United States or spent many years there. Nevertheless, being bilingual does not guarantee that person the ability to translate. Bilingualism is defined as the ability to communicate in two languages interchangeably, with the caveat that fluency in these languages might not be perfected to a professional level.
The difference between speaking two languages and perfecting them can be both slight and vast. Slight, because those who can understand and be understood in a language other than their native language have the ability to interpret ideas and concepts in a foreign language as a student of these languages. However, understanding the concept of an idea is just the first, albeit most important, step of a translator. The difference between being bilingual and being able to translate is therefore slight up to this initial starting point. Then it starts to widen as we add other components to the task of translation. This means going beyond the idea, that is, analyzing the language: identifying the style and register of a text; distinguishing and applying spelling and grammar rules; and conveying the concept of the idea maintaining the style and the register of the source language. This subtle but vast difference means a bilingual person may interpret a message in another language, but at the risk of not being able to faithfully transmit it to the source language. It is in this manner that we differentiate a professional translator with someone who is bilingual.