1
say hello (to sb)
常用结构，介词to不可省略。
She said hello to everyone in the room.
她向房间里的每个人打招呼。
问候；招呼
先理解核心含义，再看它在真实句子里的用法。
问候；招呼
a greeting said when you meet someone or begin a phone call
She said hello to everyone in the room.
她向房间里的每个人打招呼。
名词用法指打招呼时的问候语或动作；如 give me a hello（跟我打个招呼）。
“你好!”或同等问候语。
"Hello!" or an equivalent greeting.
She gave me a warm hello when I walked in.
我走进去时，她热情地跟我打了个招呼。
His cheerful hellos always make the office feel friendlier.
他愉快的问候声总让办公室感觉更友好。
I didn't get a hello from anyone at the party.
在聚会上没有人跟我打招呼。
常用结构，介词to不可省略。
She said hello to everyone in the room.
她向房间里的每个人打招呼。
非正式用法，省略介词。
Give me a hello when you get home.
到家时跟我打个招呼。
强调收到问候的动作。
I got a hello from my old friend yesterday.
我昨天收到了老朋友的问候。
Not this
Hallo, how are you?
Use this
Hello, how are you?
常见拼写错误，受德语或非标准拼写影响，正确拼写为 Hello。
Not this
Hi is more formal than Hello.
Use this
Hello is more formal than Hi.
中国学习者常误认为 Hi 比 Hello 更正式，实际上 Hello 在正式场合更常用。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
打招呼
I said hello to my teacher.
我向老师打招呼。
相互问候
They exchanged hellos and then sat down.
他们相互问候后坐下了。
匆匆打个招呼
He said a quick hello and left.
他匆匆打了个招呼就离开了。
金握手 (指入职奖金)
The company offered him a golden hello to join their team.
公司提供了一笔入职奖金让他加入团队。
嘿，稀客
Hello, stranger! I haven't seen you in ages.
嘿，稀客！好久不见。
你好，世界！
The programmer's first hello is often 'Hello, World!'
程序员的第一个问候通常是“Hello, World！”
你好，多莉！
She greeted everyone with a cheerful hello.
她愉快地向每个人打招呼。
Use hello naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
想象朋友见面挥手说‘哈喽’，记住‘hello’就是打招呼。
[object Object]
All listed words share the spelling ending 'lo' and the vowel sound /oʊ/, but note that 'hello' has stress on the second syllable (həˈloʊ), while these pattern words have stress on the first syllable. Therefore they are not perfect rhymes but useful lookalikes.
Dictionary facts from ECDICT, WIKTIONARY.