Sorry to revive an old thread but I had some questions about what has been discussed above.
I noticed that icelus said to not say "你好！好久不见了！". Is that because of the "了" at the end? Is it better to say "好久不见" instead of "好久不见了"?
or when you say "好久不见了" (with the "了"), do you usually have to add something after?
Greeting: 好久不见 "Long time no see"--It is a fixed expression ==> We don't add an extra 了, or it will break the 4-character idiom.
A: 好久不见! (It is just a cliché)
Declarative sentence: 好久不见了 "It's been a while since we last saw each other." ==> OK, now that you've made such a statement, what next? 好久不见了, 咱们喝杯咖啡, 聊聊天吧！
A: 好久不见了! (You really mean it)
B: 是啊! 快10年了!
i think you can use these two phrase when you in the face of different speakers.
i usually say 好久不见 to the normal friends as colleges,classmates.....because it 's just greeting like say hello.
but i always say 好久不见了 to my close friends.because the tone of 好久不见了 always with some emotions of touch and happy.