I used to an elective German course for a semester when I was a college student. I just studied very simple sentences at class. After I graduated from school and then I started to work, One day I had to discuss business with my German colleague and then I knocked his office door. I said “Haben Sie Zeit” in German. He was a little angry at me until I explained I was speaking to him in German. He thought I used foul language. I know that my pronunciation is too bad. The German is one of the difficult languages.