Dialogues

1. 谢谢！谢谢你！Xièxie! Xièxie nǐ!
Thanks. Thank you.
When you thank somebody for doing something, you say "xie4xie". It's very commonly used. "xie4xie" means "thanks". Or you can say "xie4xie ni3"."ni3" is you.

2. 非常感谢！Fēicháng gǎnxiè!
Thank you very much.
If you want to show your great appreciation you can say "fei1chang2 gan3xie4". "fei1chang2 gan3xie4". Thank you very much."fei1chang2" is an adverb, which means "very" or "quite". "gan3xie4" also means thanks.

3. 不用谢！Bú yòng xiè!
Don't mention it.
If someone says "thank you", what are you going to say? Well, in English it's "don't mention it". And in Chinese you can say "bu2 yong4 xie4" . Literally it means "Don't thank". "bu2 yong4" means "There's no need to…", and "xie4" means "thank".

4. 对不起。Duìbùqǐ.
Sorry.
"sorry" in Chinese you can say "dui4bu4qi3".

5. 没关系。Méi guānxi.
It's nothing.
If a person says "dui4bu4qi3"，you can respond"mei2 guan1xi". Mei2, literally means not. Guan1xi, literally means relationship.

6. 没事儿。Méi shìr.
It doesn't matter.
Besides that you can say "mei2 shi4er". Mei2 again means no or not. Shi4 means thing.