你好 (nǐhǎo) is correct, safe, and - in real life - a bit stiff, like greeting a friend with "how do you do". Here is what the street actually uses.
The everyday set
| Phrase | Meaning / when |
|---|---|
| 你好 | neutral hello; first meetings, formal |
| 您好 | polite 你好 - service staff will greet you with it |
| 早 / 早上好 | morning, casual / standard |
| 晚上好 | good evening |
| 大家好 | hello everyone - opening a class or call |
| 嗨 / 诶 | hi / hey, loanword casual |
The greetings that are not greetings
吃了吗？ ("have you eaten?") is a real greeting - a neighborly check-in, not a dinner invitation; 吃了，你呢？ answers it. 你去哪儿？ and 干嘛去？ ("where are you off to?") work the same way among friends - nobody expects a real answer; 出去一下 suffices.
Answering and moving on
你好吗？ exists but is textbooky - friends ask 最近怎么样？ ("how's it been?") or 最近忙吗？. Reply 挺好的 / 还行 / 一般般, then return the question with 你呢？ For introductions: 我叫… (name), 我姓… (surname) - surname-first order, 我姓王，叫王小明. And for the opener nobody warns you about: answering the phone is 喂 (wéi), the phone-only hello.
Saying goodbye
The mirror set: 再见 is the standard (literally "see again"), 拜拜 is the casual loanword, 明天见/回头见 (see you tomorrow / see you), 慢走 (hosts to guests - "go slowly"), 保重 ("take care" - for real farewells), and 晚安 for goodnight. On text, 拜拜 or a sticker ends the thread; 再见 reads slightly formal among friends.
Common questions
What is the correct way to say hello in Chinese?
你好 works everywhere but is formal; among friends use 早 (morning), 嗨 (hi), or a check-in like 吃了吗. With service staff or elders, 您好 is the polite form.
Do Chinese people say 你好吗?
Rarely - it reads as textbook speech. Friends ask 最近怎么样 or 最近忙吗; 你好吗 marks a learner or a formal setting.
How do you answer 吃了吗?
吃了，你呢 - "yes, and you?" It is a greeting, not a food question; a literal answer about your lunch is unnecessary.