•Hello
•Hi
•Good morning
•Good afternoon
•Good evening*
•Hey, John.
•How's it goin'?**
*Good night is a farewell (goodbye) phrase. It is NOT a greeting to use at night time.
"Good night."是用来告别（再见）的短语，并不是晚间打招呼的说法。
**Native speakers often shorten "going" to "goin" in casual greetings.
母语者在比较随意地问候时经常将"going"缩略说成"goin"。
Slang greetings in passing
Using slang in a greeting is typical between close friends. Teens often use slang when they greet each other. Certain English speaking countries also have their own popular form of "hello".
用俚语来打招呼经常发生在好朋友间，年轻人见面时常用俚语互相致意，而每个英语国家也有自己所流行的问候方式。
•Howdy
•Hiya
•Whazzup?
•Yo
•G'day (Australia)