I agree with peer comment. The actor was not learning the language but the pronunciation.
In opera, singers usually sing in different languages that they don’t speak (Italian, German, French) so they learn how to pronounce.
I grew up multilingual (3 languages at home, 3 at school) so I already have a repository of phonemes in several language families that I can draw from. I can learn to to say common phrases and sound near native in a number of languages in a month. I can also mimic accents. I noticed that someone like Trevor Noah has the same ability because they grew up multilingual.
But sounding native doesn’t mean learning the language.
Japanese also has relatively simple phonology. Just have to pay attention to pitch accent. Try sounding native in a tonal language in a month.
In opera, singers usually sing in different languages that they don’t speak (Italian, German, French) so they learn how to pronounce.
I grew up multilingual (3 languages at home, 3 at school) so I already have a repository of phonemes in several language families that I can draw from. I can learn to to say common phrases and sound near native in a number of languages in a month. I can also mimic accents. I noticed that someone like Trevor Noah has the same ability because they grew up multilingual.
But sounding native doesn’t mean learning the language.
Japanese also has relatively simple phonology. Just have to pay attention to pitch accent. Try sounding native in a tonal language in a month.