If you had to teach someone one thing, what would you teach why?

Hi there Sir [이름] ^^

Happy Tuesday!

You are right, being knowledgeable and skilled at something is an important key in teaching.

However, I think people can still learn and improve their skills when learning something new.

Thank you for your doing your homework.

I hope that you are having a great day.
Talk to you soon.

Teacher Nina

In order to teach someone, I should be knowledgeable about the subject and having rich experience is necessary. 

>> In order to teach someone, I should be knowledgeable about the subject and have lots of experience is necessary. 

However, thinking about what area I’m good at, I cannot pinpoint anything, neither proudly say that I’m an expert at something.

>> correct

For instance, I don’t like people who are rude and hope that they are educated.

>> correct

However, I cannot be someone who teaches them because I might look impolite and behave badly from other people’s point of view.

>> correct

Talking about academy, I might want to teach someone on how to invest wisely and make a big profit because I’m very much interested in earning money like everybody does. 

>> correct

However, I have not studied it and actually failed many times because of careless and impulsive investment. 

>> correct

Thorough analysis and research should have been carried out before making an investment decision. 

>> Did you mean: Thorough analysis and research should have been carried out before making a decision about investing something.  

However, here is an irony. 

>> correct 

Real rich people do not teach or disclose information about making money, some books say.

>> Better: Some books say. Real rich people do not teach or disclose information about making money.