How does English borrow from other languages?
Borrowing and lending of words happens because of cultural contact between two communities that speak different languages. Often, the dominant culture (or the culture perceived to have more prestige) lends more words than it borrows, so the process of exchange is usually asymmetrical.
Why do we need to borrow words from other languages?
Sometimes, however, a language does not possess all the words necessary for it to capture all its experiences. At such times, it has to borrow words and expressions from other languages that come in contact with it. Such borrowed items help in enriching, expanding and developing the language.