There's a huge difference between being fluent in a language and being on the level of a simultaneous interpreter or translator. My ex was born in France and lived there until he was 4. He still speaks French fluently, as well as English, and he doesn't have an accent in either one! He is also fluent in Spanish and Portuguese. I think when you grow up speaking more than one language, others come pretty easily.

My ex does translate documents for his work, but is more comfortable going from French/Spanish/Portuguese towards English. He does NOT do simultaneous interpretation. That takes formal training and just the right brain wiring. I do have a friend who was an intrepreter for the US State Department. He was born in Mississippi and lived in France for a few years. He just had a knack. He could do it French-English and English-French. He once had me try it English-English by watching the news and just repeating what the newscaster said in the same language. It was very difficult.

English is my first language, but I am fluent in French. On my resume I put "Fluent in French" no problem. But I'm not in the interpretation or translation business. I did have to use French from time to time at my old job because we had projects in Africa. I got by just fine even though the accent was sometimes challenging. I also put that I'm a dual national (US-France) because that might open some opportunities. So far it hasn't, but it might.

The next level down from fluency is "conversant." I used to put that down for Spanish, but it's gotten rusty, so I took it off. Gotta get back to my Rosetta Stone.