The very first thing you learn to say in any new language is, without doubt, how to greet people. And there’s a good reason for that – you can’t possibly strike up (=start) a conversation without saying hello first. Well, technically speaking, you can, but we don’t do that in polite society (=educated and well-mannered people).
Hello is a universal greeting – it works at any time of day and in any situation, especially with people you don’t know well and older people.
Hello Mrs Smith. How are you today?
It’s also the word we use when answering the phone.
Hello. – Hi Jenny, it’s Katy. – Oh, hi Katy!
Hello there can be used to address either one person or a group of people.
Hello there! It’s ages since I last saw you. How have you been?
We also use it rather informally when writing to someone whose name we don’t know (or can’t remember!). For example, you want to buy something on Ebay but have questions to ask the seller. Hello (or Hi) there is a perfectly acceptable way of starting your message.
Then, there’s hi, which these days is by far the most popular greeting among native English speakers as it’s friendlier and less formal than hello. It’s used both in conversation in informal writing, i.e. emails and text messages, with family and friends, colleagues and clients, people who do things for us, such as shop assistants and waiters, and so on. The only restriction in its use is the age difference – don’t say hi to anyone who’s much older than you, unless you’re on intimate terms with them as I am with my parents-in-law, for example.
Hiya is even more informal and, I’d say, very relaxed and therefore acceptable only when you know the person really well.
Hiay, Jack! Long time no see.
Good morning/afternoon/evening are to be used at a particular time of day. In real life the only one of them that you still hear all the time is good morning with good often being dropped.
Good morning Nick! – Morning!
Good afternoon and good evening are used in more formal situations.
Good night is only used when you’re leaving someone or they’re leaving at night.
(guests leaving when the party’s over) Thanks a lot for having us! – Thanks for coming! Good night!
We also say it before going to sleep. In this case good is often dropped and night is said twice, especially to children.
Night night, sleep tight!
And this brings us to ways of saying goodbye. Goodbye is now used only in rather formal situations. The everyday life favourite, for the same reasons why native English speakers prefer hi to hello, is bye (and its even friendlier and more informal variant bye-bye).
If you know someone well and chances are you’ll see each other again, you can say See you!
For occasions when the new encounter isn’t far away there’s See you soon!, and if it’s likely to happen on the same day – See you shortly! and See you later!
See you around! implies you might see each other again, though you haven’t arranged that.
If you have arranged to meet again, you can mention it when saying goodbye.
Bye Steve! – Bye John! See you on Wednesday/the 17th!
When it’s someone you see every day, e.g. your work colleagues, you can use See you tomorrow! or, on Friday evening, See you next week!
When saying goodbye, we often add a good wish to it.
Bye-bye! Have a nice day!
Bye! Have a lovely weekend!
Bye! (Have a) safe journey!
Hope I’ve covered everything. If you have any questions, please feel free to ask in the comments.
Bye for now!