When I was a junior high student, I started to learn English.  In each lesson, we had to repeat the following conversation with a teacher.

(S=students; T=a teacher):
 
T: How are you?
S: I’m fine, thank you. And you?
T: I’m fine, thank you.
 
So, those phrases were inputted into our brain no matter what. But, later, I noticed that, after I attended UCLA in California, people usually say “good” instead of “fine.”  Sometimes I hear “I’m fine,” though.
 
Anyway, most of Japanese have experienced the repetition for three years. So, if you go to Japan and ask anyone around you “how are you?” you would get an automatic reply, “I’m fine, thank you.”
 
“How are you?” is hard to translate because the Japanese language doesn’t have an equivalent expression. The phrase is often interpreted “Gen-ki?” But I think that is a little bit different.
 
Originally, “gen-ki” is a word that describes a state of being healthy or having a lot of energy or spirits, so, I understand “how are you?” can be translated into “gen-ki?.”
 
But when I worked in Tokyo with an American team, I always felt a little bit strange whenever I was asked, “Gen-ki-de-su-ka?”  That is a polite way of saying “gen-ki?”
 
At that time, I was not fluent in English, so I just wondered why they were asking me if I was “gen-ki” every day and thought like this. Did I look sick or depressed yesterday? That’s why they were asking me if I felt better?
 
Now I know that’s just a misunderstanding. They just wanted to say “how are you?” in Japanese to me as a greeting.
 
Sometimes, direct translation doesn’t work well because, in other cultures, people don’t have the same custom that you have. I have learned this a lot while I’ve been learning English and Spanish.

 
Then, when do we use “gen-ki?” to a person?
 
When I say “gen-ki?” to a friend in Japanese, the question implies that I haven’t seen the friend for a while. In this context, the meaning of “gen-ki?” is “how have you been?”
 
How long depends on a person. Maybe at least a month or so. 
 
However, in California, a person at the casher in any supermarkets and a sales staff at any shops say “how are you?’ when they see a customer. It is just a greeting.
 
Japanese people don’t ask strangers “gen-ki?” So, sales staff will never say “gen-ki?’ as Californians say “how are you?”
 
So, I think that the translation of “How are you?” might be “Gen-ki?” in Japanese, but we usually don’t ask “gen-ki?” to others without any reasons.
 
The question using “gen-ki” might be limited like the following situations:
 
(1) When you haven’t seen a friend or an acquaintance for a while and you see him/her on the day, or when you have a chance to talk to him/her over the phone.
 
So, when you want to know how the person has been doing, you can use,”Gen-ki?” In this case, the past tense is often used, which is “gen-ki-da-ta?’  This means, “How have you been?”
 
(2) When you want to ask “feel better?”
 
You want to know if a person feels better because you know the person wasn’t in a good condition such as sickness, depression, and so on.  In this case, another type of past tense “gen-ki-ni-na-ta?” is used, which means “became gen-ki.” (=Feel better?)
 
Now I know American culture, so I finally came to understand why English speakers, my coworkers, often asked me in the morning if I was “gen-ki” in the office.
 
So, please remember that “How are you?” cannot be directly translated in a simple word.
 
So, anyway, please learn this word, “gen-ki” today. If somebody asks you, “Gen-ki?,” you can simply answer,”gen-ki.”
 
Thanks for reading!