不客气  (bú kèqi) - you’re welcome

谢谢你！不客气！

Thank you! You're welcome!

当然 (dāngrán) - of course

当然可以！
Of course you can!
是，是啊，当然
Yes, yes, of course.

对不起 (duìbuqǐ) - sorry

对、对不起
You're right, I'm sorry.
你对不起我
You do me wrong.
 

没关系  (méi guānxi) - no problem / you’re welcome

甜点儿没关系
I don't mind if it's sweet.
没关系， 我来做
Don't worry. I'll do it.
 

请  (qǐng) - please

请开灯
Turn on the light, please.
请上车
Please get into the car.