How to say in Chinese the follwing expressions? (please write in pinyin)
Expressions such as:
1. Really?
2. That's good!
3. I understand you.
4. I have to go now.
5. I forgot.
6. I hope to see you again.
7. See you tomorrow.
8. I am happy to know you.
9. Congratulations!
10. Good luck!

Question

Answer

1. 真的假的? - zhen de jia de?
2. 很不错! - hen bu cuo!
3. 理解. - li jie. 
4. 我得走了 - wo dei zou le. 
5. 我忘了 - wo wang le.
6. 下回见 - xia hui jian
7. 明天见 - ming tian jian
8. 很高兴认识你 - hen gao xing ren shi ni
9. 恭喜! - Gong xi
10. 好运! - hao yun

PS: those are just one of the various ways to express in chinese, besides some of the expression on the list are not in an authentic way to apply in China. let me say that it belongs to the multi-culture expressons.

Answer

1.真的（吗）？zhen1 de(ma)? | 真的假的？ zhen1 de jia3 de?
2.很好。hen3 hao3 | 不错！ bu2 cuo4!
3.明白 ming2 bai2 | 了解 liao2 jie3 | 理解 li2 jie3 
4.我得走了 wo3 de3 zou3 le
5.我忘了 wo3 wang4 le
6.希望下次还能见面 xi1 wang4 xia4 ci4 hai2 neng2 jian4 mian4 | 回见 hui2 jian4 | 再见 zai4 jian4
7.明天见 ming2 tian1 jian4 |明儿见 miner jian4
8.见到你很高兴 jian4 dao4 ni3 hen3 gao1 xing4
9.恭喜! - Gong1 xi3
10.好运 hao3 yun4

Answer

Really?  -  不是吧？bu shi ba?
That's good! - 太好了！tai hao le!
I understand you - 我懂 wo dong
 I have to go now  -  我该走了。wo gai zou le
 I forgot  -  我搞忘了。wo gao wang le
 I am happy to know you - 
I hope to see you again  -  期待与你再次相见 qi dai yu ni zai ci xiang jian
See you tomorrow 明天见 ming tian jian 
 I am happy to know you  认识你太高兴了 ren shi ni tai gao xing le
Congratulations - 恭喜你！gong xi ni
Good luck  -  一路顺风 yi lu shun feng