USAGE NOTE 用法说明: customer,shopper, client, patient, and 和 guest
These words all mean someone who buys or receives goods or services. If you go out and buy things, you are a shopper, but if you buy something in a particular shop, you are that shop's customer. 这些词都指购买货物或接受服务的人。如果你外出购物，你就是 shopper（购物者），但如果你在某个商店购物，你就是那家商店的 customer（顾客）:
The mall was full of shoppers. 购物中心里挤满了购物者。
We don't get many customers in the evening. 我们晚上没有很多顾客。
If you are paying someone such as a lawyer for professional services, you are a client, but if you are seeing a doctor, you are a patient. If you are staying in a hotel, you are a guest. 如果你付费接受律师等人士的专业服务，你就是 client（委托人，当事人），但如果你去看医生，你便是 patient（病人）。如果你住旅馆，你就是 guest（客人，旅客）。