It seems a paradox! If that person speaks two or more languages, he understands everything and can provide language translation services. No, wait, unfortunately, it is not that simple!
Bilingualism i.e. speaking two languages is a complex linguistic and psychological phenomenon. Language can be acquired in different ways and to different degrees, and at different ages too.
Some children never progress beyond the language they were exposed to in their family, for example, talking to their grandparents. They never had any formal education in their “non-dominant” language, as it is sometimes called. They will clearly be unable to have a conversation on technical or specialized topics.
For that, you actually need to study these topics (and accompanying terminology) for an extended period of time.
This is one of the components of the education and training professional interpreters have. They study a variety of topics in all their languages and terminology in these languages: history, chemistry, biology, economics, computers, nanotechnology, art being just a few.
But, on the other hand, you may say, our hypothetical bilingual person is an expert in his field. No doubt about that. He may very well be, and he will be able to interpret very well, as long as the conversation does not stray away from his area of expertise.
If speakers turn from particle physics to Shakespeare to growing rabbits to the latest economic theories, as it not infrequently happens (watch a few TED videos, for example), most bilinguals will, unfortunately, be hopelessly lost.
Professional interpreters will never know everything about a particular topic, however, by virtue of their education and insatiable curiosity, they possess knowledge and vocabulary on a broad variety of topics, and, sometimes, it does save the day.
As someone said, experts know everything about nothing, interpreters know nothing about everything.
When bilinguals, actually, attempt to interpret, there is another additional difficulty. During a conference on cardiology in Russia, one delegate was not particularly “happy” with the quality of the interpretation and asked if he could sit in the booth and interpret simultaneously. By all means! For the next 5 minutes – until he ripped off his headset in utter frustration, all the delegates could hear in their headsets was: ”errrrrrrrr…mmmmmmmm..and the aorta…. Yeah..well.. yes, I understand it, just give me time…..mmmmmm….”
Interpretation, especially simultaneous interpretation, is a highly specialized technical skill. No one in his sound mind would attempt to pilot a Boeing 777 full of passengers, if you have never done it before.
Some people tend to think, however, that interpretation so easy that “my driver can do it” i.e. that he, actually, has all the required skills and will successfully navigate the bilingual discussion past the Scylla and Charybdis of technical, legal or corporate terminology.
This thing that distinguishes professional interpreters is not just the knowledge of two languages. Each language can be represented as a separate realm.
What distinguishes professional interpreters, however, is set of connections, links between these languages. These strong links are formed during formal interpreter training.
While for a bilingual languages exist in isolation, for a professional interpreter they are integrated into a living and breathing organism, when you know very well in advance what particular difficulties you may encounter going into English or into Russian, for example, and which strategies you may use out of your large professional arsenal.
Add to that purely interpretation skills: simultaneous interpretation, consecutive interpretation, note-taking techniques, memory training, public speaking skills, and voice training, and you will see that being an interpreter is a much more complicated set of skills than simple bilingualism.
In the final analysis, good professional interpreters charge, they need to be booked well in advance, but just like with every quality service, there is no substitute for experience, skill, and professional training.
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