Dear Sir/ Madam,
I am writing to ask for how to use "how do you do" because it is very hard to say in my country Asia, Cambodia. Especially, for the most of the children who are just four or five years old they can not remember what time that they should say the words as goodmorning, goodafternoon, or goodevening. So they can say "how do you do" dayfully, can't they?
This is the big deal that stuck in my mind about two weeks ago. I firmly hope all of you will help me to deal with this issue. And I am looking forward to receiving your generosity.