Have you tried to translate a movie script into Spanish? What are the main difficulties you have found? What do you think are the keys to make a good audiovisual translation? Which one is the most important when you want to make a good translation: culture or language?
If your answer to the first question was yes, you have observed there are some expressions or onomatopoeias difficult to understand or to translate. Maybe, you have used some dictionaries or web sites you considered very good language database. Perhaps, you have asked to your friends without finding a good answer. If you are a very curious person, you have requested help to an expert. But, all of this process needs a lot of time. This is very similar to a translator work.
When we talk about a book or text translation is easier than an audiovisual one, why? Because you have to think about orality and topic change. Believe one of them is not important could be the reason of bad adaptations in some movies and series we watch in a theater or our TV. Bilingual people can declare to watch a movie or a series episode in its original language is always better than to look for a paraphrased version.
Culture or language? If you have visited some different South American countries you have noticed how some expressions and words change their meanings or their pronunciations from one place to another. If you don’t, it’s impossible you can use those differences for making a very good translation. A similar situation could happen with a person who knows a lot of languages or only two but haven’t visited any place related with some of them, he or she can know the language in a perfect academic way but he or she could not be sure about some cultural aspects about the use of them in their original birthplaces. How can this person give you a correct guidance about the meaning of some colloquial or very used expressions? Even, It would be different if he or she has had contact, in some way, with these language native speakers. It can help you.
What about tools as Google translator? As we have said all along this text it could be very hard for a person who doesn´t have cultural contact with any language to translate a text, movie, etc in it, even if he or she knows it, a machine could not have enough information for storing all the differences that we can find in only one expression used by people from different countries in an unique zone. What could be the reliability degree that a machine can give us?
In conclusion, if you want to have a very good knowledge about a language you need to know its culture. The best way to do it is to talk to Native Speakers. Think about it if you want to be an expert in any language.