说英语国家的不同问候方式

Spoken greetings are customary or ritualised words or phrases used to introduce oneself or to greet someone. In English, some common verbal greetings are:

"Hello" — the most common verbal greeting in English-speaking countries, and related to "Hullo" (UK English, now old-fashioned) and "Hallo". Suitable for formal and informal usage.
"Hi", related to "Hiya", both being less formal for 'hello' but very widely used nowadays. It is classified in dictionaries as a sentence substitute. "Hi" is relatively new, having become popular in the 1920s in the USA and then spread throughout English-speaking populations around the world, and even into other languages.
"Hey", has become fairly commonplace as a greeting in informal USA English, but is considered impolite in UK English to use as a greeting (Cambridge English dictionary says "used as a way of attracting someone's attention, som