These are all words for an amount of money that you pay or are expected to pay, or for the act of paying.以上各词均指款额、款项、付款。
payment an amount of money that you pay or are expected to pay; the act of paying指款额、款项、付款：◆ten monthly payments of $50每月付款 50 美元，十次付清◆payment in advance预先付款
premium an amount of money that you pay once or regularly for an insurance policy; an extra payment added to the basic rate; a higher amount of money than usual指保险费、额外费用、附加费、溢价：◆an insurance premium保险费◆a premium for express delivery快递附加费
contribution a sum of money that you pay regularly to your employer or the government in order to pay for benefits such as health insurance, a pension, etc.指（给雇主或政府用作医疗保险、养老金等福利的）定期缴款：◆You can increase your monthly contributions to the pension plan.你可以增加你的养老金计划每月供款。
subscription an amount of money you pay in advance to receive regular copies of a newspaper or magazine or to receive a service指（报刊、杂志的）订阅费、订购款，（服务的）用户费：◆a subscription to 'Newsweek'《新闻周刊》的订阅费
repayment(BrE) an amount of money that you pay regularly to a bank, etc. until you have returned all the money that you owe; the act of paying this money指按期偿还的款项、分期偿还额、偿还债务、归还借款：◆the repayments on the loan贷款的分期偿还额
deposit an amount of money that you pay as the first part of a larger payment指订金：◆We've put down a 5% deposit on the house.我们已支付了房款的 5% 作为订金。
instalment one of a number of payments that you make regularly over a period of time until you have paid for sth指分期付款的一期付款：◆We paid for the car by/in instalments.我们以分期付款买了这辆车。