Something I'm told about communication

Recently I've learning English conversation in online. Today I write something I'm told in the lesson.

Something I'm told

 The teacher said that people in overseas don't listen to our speaking. Especially Japanese tend to nervous and don't say something clearly, so it makes him irritate, and as a result, they become to look down to us.
 Teacher said, for example, when I want to buy cheeseburger in McDonalds, only one thing to say for you is that "I want to buy one cheeseburger". But if you didn't show it clearly and talk something longer than needed and unclearly, clerk will not take me seriously even if she is a clerk. So, you need to say only things you must tell someone, and you should say it clearly, in other words, speak out it clearly.
 Teacher said that this is the only way to make people in overseas treat us seriously. And if they don't treat us seriously, they never understand something we say.
 Thus, something you should do first is to be and speak clearly to not allow them to look down to us, and to make them serious. And almost of Japanese fails in this point. 

Other aspect of it

This is very likely opinion. And I think exist of the other point about it. I have let me to speak small. It's because my voice is small and don't have confidence in myself. And maybe as a result, I became let me not to have my opinion clearly. It is maybe one result of treated not seriously, too.

Anyway

Not to be clear leads failure of communication. This is similar to relation between the biggest problem of me and one of main characteristics of me. 

So, I tried to speak clearly with good voice as long as I can speak. Replying of me became faster a little, but maybe the accuracy of reply is not improved. 

I'll continue to think the way to concur this.