Abilities to do this range widely with individuals.
Leaving that aside, there is a concept of linguistic distance from people´s first language, which makes it easier or harder to learn another language. French and English are very close to each other, as are Arabic and Hebrew, the Scandinavian languages are also all very close to each other (a little further from English), except for Finnish of course, which is kind of out there on its own. There is a nice recent paper looking at this in the academic context:
Essentially how far your native tongue is from the language you are attempting to learn will drastically affect how long it takes to learn it for most people.
Leaving that aside, there is a concept of linguistic distance from people´s first language, which makes it easier or harder to learn another language. French and English are very close to each other, as are Arabic and Hebrew, the Scandinavian languages are also all very close to each other (a little further from English), except for Finnish of course, which is kind of out there on its own. There is a nice recent paper looking at this in the academic context:
https://www.sciencedirect.com/science/article/pii/S004873332...
Essentially how far your native tongue is from the language you are attempting to learn will drastically affect how long it takes to learn it for most people.