Multilingual idiot here.
Fluent French, Spanish, English, good Dutch, some Portuguese, a little German.
Can understand some other languages, like Italian or Scandinavians.
Can read Greek or Russian alphabet as an example.
Sorry, I slept during my Latin/Greek classes in school.
xxx
French is excellent if you often operate in Africa.
Spanish is South America. They might understand some Spanish in Brazil.
I think Mandarin is slowly taking over Japanese as Asian business language.
xxx
English...?
In South America, rural areas, English is worthless.
In Miami, English is "second language"... I met some tourists speaking English there.
Happy contrails