Listen to the whole passage
Listen to the whole passage once first, then practice sentence by sentence.
The first line is the other person opening the conversation; the "You" lines are suggestions for you to practice saying in this scenario (not a back-and-forth dialogue).
A cashier
你好。你要买什么？
Hello. What would you like to buy?
You
你好！
Hello!
You
我要买一瓶水。
I'd like to buy a bottle of water.
You
这个多少钱？
How much is this?
You
一共多少钱？
How much is it altogether?
You
给你钱。
Here's the money.
You
请找我钱。
Please give me my change.
You
谢谢，再见！
Thank you, goodbye!