A person who is fluent in a language can easily speak and write in that tongue. Many people are fluent in ten or more languages, but very few have become fluent in more than 20.
Perhaps the greatest master of language-learning of all time was Joseph Caspar, who was born in Italy in the 18th century. Caspar was first a carpenter, but later became a priest and then a cardinal, taking the name of Cardinal Mezzofanti.
No one knows for sure how many languages Cardinal Mezzofanti could speak, but it was probably more than 30. Some people said he could speak 53 languages well, and could understand most of what was said in more than 100 tongues! The language that gave him the most trouble was Chinese, it took him four months to learn it!
Though Mezzofanti could speak the languages of dozens of nations, he never set foot out of Italy in his entire life!