Allo,
It is easy to answer this question.
I understand you dont understand, because you are still a
student.
But, once you enter an adult world, a world where social status is
attached very closely to money, you will understand.
Simply, asking how much money someone earn, is rude, because you
are basically trying to size up someone on his socio-economic
status. He will be hesitant to answer you.
If I may use an analogy,
It is similar like someone ask you how long is your d1ck.
And this is a similar predicament of why you should not ask an
adult woman of her age.
Simply, past a certain age, women must not be asked for her age.
You can only inquire that information when she is still in her
teenage years or early 20s.
In fact, when you wish to know more about a person's career, a more
polite way is to ask in a general manner, which line is he working
in. For instance, he may say, advertising, or IT.
It is not halal to ask in a specific manner, for example, what is
your job? It will force him to say, I'm the cleaning uncle of my
housing block. A more graceful general question will enable him to
say, I'm in sanitation line.
This will put him into more ease, and your relationship more
graceful.
