1、good bye相当于词组，而good-bye是名词，也是感叹词；goodbye与good-bye都可以单独使用，表示“再见”的意思。goodbye与good-bye都是正确的表达，可以表达“再见”的意思。
2、关于“good bye”例句：
Goodbye! It was great to meet you. 再见！认识你很高兴。
She didn't even say goodbye to her mother . 她甚至没有向母亲道个别。
We waved them goodbye . 我们向他们挥手告别。
We've already said our goodbyes. 我们已经道别了。
3、“good-bye”例句：
They hurried into the city to say good-bye to us. 他们赶进城来和我们告别。
She left without so much as saying “ good-bye ”. 她甚至连“再见”都没说就走了。
We said good-bye to each other at the station. 我们是在车站分手的。
I left in such a hurry that I didn't have time to say good-bye to you. 临行匆忙，未能向你告别。
扩展资料
1、“good bye”是普遍应用的口头交流的语言形式，非书面语。英语口语灵活多变，多因场合与发言者不同而被自由使用。与口语相对，书面英语是在口语的基础上发展出来的，用于书面表达的语言。
2、常用的口语问句有：
How are you doing? 你好吗？
What's up? 什么事？
Could you do me a favor? 能不能帮我一个忙？
What are you studying? 你主修什么的？
小琪1128
