If you speak two or more languages, you can interpret and translate.
Bilingualism (or multilingualism) is just a pre-requisite for professional interpreters and translators. Both translation and interpretation require an aptitude and an extensive training similar in its intensity to the training received by professional musicians or dancers.
If you can translate, you also can interpret.
Each of these activities requires a unique set of skills.
“Madam Interpreter, just repeat word-for-word what was said!”
“Word-for-word interpretation” is an oxymoron. Interpreters work with units of meaning (units of information). There are very few direct and singular lexical equivalents among different languages, leave alone syntax and grammar. Words are just pegs to hang ideas on. Producing complete and accurate interpretation is an enormous challenge.
Why are interpreters so nosy? Why do they need to review case materials prior to interpreting a court hearing or a deposition? They just repeat what was said. It’s not their business to snoop around.
Interpretation is an extremely complex mental process. An interpreter performs multiple mental tasks and makes tens of linguistic decision in a split second. The better the interpreter is familiar with the content of a speech or with the circumstances of a case, the better she performs. In addition, we comply with the same confidentiality requirements as medical and legal professionals as well as diplomats.