The interpreter and the translator do the same thing. They grasp the subject matter of source language to deliver it in another yet the two are not interchangeable. Each of this profession has equivalent strengths, however, translation is slightly demanding. A translator has to have the interpreting skills; they must first interpret (to himself or colleague) text for them to translate it while an interpreter can do without translating tasks. For example, they do not need to refer to dictionaries and other tools to deliver. There are rare cases of professionals who can do both interpretation and translation but it is advisable to hire specialists in either of the two for perfection.
Difference in knowledge. Interpreting does not necessarily mean converting word after word to the target language. Interpreting involves elaborating the meaning for the live audience to understand, possibly without using the exact sentences while translating is restricted to converting the meaning of a source language text by using tools of an equivalent target language text. Therefore what is more important to an interpreter is to have the in-depth knowledge of the current culture of the people who speak the language he is interpreting as well as its jargon updates in order to be expressive enough. On the other hand, the translator has to have the wider knowledge of both ancient and current culture to have a wider vocabulary of the language to deliver accurate meaning.
Writing is different from speaking. An interpreter is a speaker while a translator is a writer. The way a statement is spoken is different from the way it is written. Considering grammar or and accuracy, interpretation does not rely on accuracy and grammar as long as the audience is able to understand what the interpreter has faithfully stated while translation (written) is emphatic on grammar accuracy. Anyone can interpret as long as they are inborn field specialists because they have the ability to make the audience understand while a translator must be a linguist, trained to scrutinize source text to determine the right vocabulary for the target language to maintain sense of the subject matter.
Natural Talent. There are people who are good in public speaking while others are introverts but good in writing. This could explain why some interpreters cannot be translators. It is two separate inborn talents. Translation agencies which offer to exceptional services must have discovered that from the beginning, during their scrupulous interviews thus recruiting wisely. Therefore an interpreter is expressive in speech while a translator is, in writing.
Difference in experience. Interpreters have to translate sentence after sentence, at most a paragraph, simultaneously .Interpreters speak directly to the audience, if they are to have stops, or break in to interpret along speech, the audience might end up lose the flow of the message. Translators first read the whole block of text to graspof the meaning of a source-language text to determine the equivalent target-language vocabulary to use. Therefore interpreters and translators might find switching tasks hard after their longtime of service. Each should perform the tasks they are specialized in and conversant with for excellence.
Difference in performance. Translating is a solitary professional. If more than one translator handles the document, they might interfere with the meaning of text. On the other hand, for one to interpret solely, they have to have the capacity to handle speech that requires instant response of conversion no matter the speed or opt to interpret in pairs, one to interpret as the other monitors accuracy, to anticipate mental breakdown. A person who is used to performing in partnership might be bored by the work of a translator, whose pace of performance is necessarily slower.