利息

When we talk about interest in a financial sense, we are talking about the 'cost of money.' Think of it as a rental fee. If you rent a car, you pay the owner for the privilege of using it. Similarly, when you borrow money from a bank, you pay interest for the privilege of using their cash.

The amount of interest is usually determined by an interest rate, which is a percentage of the total amount borrowed, known as the principal. The higher the risk for the lender, or the longer you keep the money, the higher the interest usually is. It is a fundamental concept in global economics, affecting everything from your savings account to the national debt.

The word interest comes from the Latin word interesse, which literally means 'to be between' or 'to make a difference.' In medieval Latin, it evolved to refer to the compensation paid for damage or loss, specifically the loss a lender suffered by not having their money available.

Historically, charging interest was often controversial. Many ancient cultures and religious traditions, including early Christianity and Islam, viewed usury—the charging of excessive interest—as immoral. Over time, as banking systems evolved in the Renaissance, the concept of interest became standardized as a necessary tool for capital investment and economic growth. It transitioned from a 'sin' to a cornerstone of modern financial stability.

You will hear interest used in both casual and formal settings. In casual conversation, you might say, 'I'm paying a lot of interest on my credit card.' In a professional or academic setting, you might discuss 'compounding interest rates' or 'fiscal policy and interest adjustments.'

Common collocations include accrue interest, pay interest, earn interest, and interest rate. Note that while interest can also mean 'curiosity' (e.g., 'I have an interest in art'), the financial meaning is almost always used with verbs involving payment, gain, or rates.

1. Pay interest: To give money back to a lender on top of the original loan. 2. Compound interest: Interest calculated on the initial principal and also on the accumulated interest of previous periods. 3. Interest-free: A loan or credit offer that requires no extra payment. 4. In someone's best interest: Doing what is most beneficial for a person. 5. Self-interest: Acting in a way that benefits oneself.

Interest is an uncountable noun when referring to money. You don't say 'two interests,' but rather 'a high amount of interest.' The pronunciation is tricky; in American English, it is often pronounced as two syllables: /ˈɪntrəst/.

Rhyming words include disinterest and uninterested. When using it in a sentence, it often acts as the subject of a passive verb (e.g., 'The interest was calculated by the bank'). Always use the singular verb form because it is uncountable.