There is no "best" way to learn a language, because everyone learns slightly differently. Though many language teachers agree that immersion is an excellent way to learn a language.
Since there are many thousands of languages in the world, I somehow doubt that there is any person who has learned them all.
Marco Polo was well educated and spoke four languages. He was taught by his father, uncle, private tutors, and learned a lot while traveling abroad.
The opposite of "taught" could be "learned."
Philology is the study of ancient languages and the history associated with them. It was the field of study that Professor Tolkien taught. He leaned heavily on the legends and myths he learned while studying to create the languages used in his books.
learned e.g we were taught by learned professors
Something learned is something that someone has taught to you and you have understood.
Katherine Mitchell
A teacher probably taught him much of the math that he learned. Teachers are great at teaching math to students.
The record for the number of languages learned by one person is 69 languages. This record is held by Ziad Fazah, a Lebanese polyglot who has demonstrated proficiency in multiple languages.
The word "autodidact" is used for an entirely self-taught learned person.
English and French...
A learned behavior in not instinctive but must be taught or acquired through learning.