Well, the most courteous man I know is my uncle, who’s my father’s little brother. We are pretty close. He’s only 10 years older than me and we always hang out together. He’s well educated, I mean, he just got his doctoral degree. He’s been to a bunch of formal occasions, and he’s quite familiar with social etiquette.
Here are some few examples:
Whenever he’s out with someone, he’s always properly dressed. I didn’t get why he would go through so much trouble to “impress” others, but he explained, the whole point was not to impress, but to show respect.
And he’s super modest when talking to others. Besides, he’s a good listener. He never cuts others off. It always feels good when I have a conversation with him.
And he’s extremely polite when interacting with waiters and taxi drivers. He would say thank you many times after he’s been helped.
On top of that, he pays attention to small details in our daily life, like knocking on doors before entering a room, holding the door for others behind him, and holding the elevator when he sees someone rushing to the door.
So you see, he’s really a nice person, and he’s a good influence on me. Spending time with him has helped me become a better person.
Courteous = polite, especially in a way that shows respect此处就是为了替换一下polite，例如：
a courteous young man
The hotel staff are friendly and courteous.
Etiquette = the formal rules of correct or polite behavior in society or among members of a particular profession如果感觉记忆有难度的话，说social manners也OK.
A good listener = somebody who you can rely on to listen with attention or sympathy就是我们常说的“很好的聆听者”。
Cut somebody/something off = to interrupt somebody and stop them from speaking，例如：
My explanation was cut off by loud protests.
On top of that = also, additionally, moreover. (Wiktionary) 不过也有一种用法是强调用于列举一堆不好的事情的，例如The Free Dictionary给出的解释：in addition to the bad thing already mentioned，例如We missed the bus, and on top of that it started raining.