HERE are some useful sentences to show your courtesy or give compliment in China:

Can I practice Chinese with you?
- Wo hé ni liàn xí zhong wén hao ma? 

Could you please call (name of person) for me?
- Qing nín tì4 wo gei (name of person) da gè diàn huà, hao ma? 

Do you know how to speak Cantonese also?
- Ni ye huì shuo Guang Dong huà ma? 

Glad to meet you!
- Jiàn dào ni hen gao xìng!  

Goodbye!
- Zài jiàn!  

Good day!
- Wu an!   

Good evening!
- Wan shàng hao!  

Good luck!
- Zhù ni hao yùn!  

Good morning!
- Zao chén hao! 

Good night!
- Wan an.   

Greeting someone in a slang manner.
- Hèi, ger1 menr! (to a peer male with whom you must be üery familiar, or it is considered to be üery rude.) 

Hi, is (name of person) Home (here)?
- Wèi, (name of person) zài jia ma? 

Hope to see you again next time.
- Xi wàng xià cì zài jiàn dào ni.  

How are you, Mr. Wang
- Ni hao, wáng xian sheng! 

How are you?
- Ni hao!  

How do you say ... in Chinese? ...
- (an English word or phrase) de zhong wén zen me shuo? 

How's your dad and mom?
- Ni de bà ba ma ma hao ma? 

How old are you?
- Ni duo dà le?  

I am John.
- Wo shì Yue Hàn.  

I don't speak English.
- Wo bú huì jiang ying yu. 

I think you are cute.
- Wo jué de ni hen ke ài. 

kind regards
- wèn hao 

Let me introduce you to each other.
- Wo gei ni men jiè shào yí xià.  

May I speak with (name of person)?
- Wo ke yi hé (name of person) shuo huà ma? 

Mr./Mrs/Ms./Prof. (to a teacher)
- Lao shi 

My first name is John and my last name is Smith
- Wo jiào Yue Hàn, xìng shi mì si.  

Say hi to Prof. Li!
- Dài wèn Li jiào shòu hao.  

See you again.
- Zài jiàn!  

See you next time.
- Zài huì!  

See you tomorrow!
- Míng2 tian jiàn.  

So-so.
- Ma ma hu hu. 

Speak slowly so that I can learn it.
- Shuo de màn dianr3, wo hao xué. 

Stay in, please.
- Qing liú bù. 

Sorry!
- Duì4 Bù Qi! 

Welcome to my home.
- Huan yíng dào wo jia zuò kè.  

What is your name?
- Ni guì xìng?  

Wish you a happy journey!
- Zhù ni lu tú yú kuài! 

Wish you a plain sailing home!
- Zhù ni yí lù shùn feng!  

Wish you a safe journey back home!
- Zhù ni yí lù píng an! 

You look pretty young.
- Ni kàn shàng qù méi nà me dà.  

You look smart in that dress.
- Ni chuan zhè shen yi fu hen shuài.  

You look very young.
- Ni de yàng zi hen nián qing.