• 请问，哪儿卖…？Qǐngwèn, nǎr mài…? May I ask, where can I get (buy)...

• 卖…什么的，在…(place)…。Mài…shénme de, zài…The one that sells…is+ (place).

        E.g. 卖箱子的在三楼/层。

• 小姐，这个…，给我看看。Xiǎojiě,zhè ge…,gěi wǒ kànkàn....Could I have a look at this...

• …有大一点儿的吗？Yǒu dà yīdiǎn er de ma? Do you have anything bigger?

• 我就要…吧。Wǒ jiù yào…ba. I would just like to have...

• …和…都一样价钱吗？…hé…dōu yīyàng jiàqián ma? Are ... and ... the same price?

• 小姐，这是…刚从您这儿买的…，…以后我发现…。Xiǎojiě, zhè shì... Gāng cóng nín zhèr mǎi de... ... Yǐhòu wǒ fāxiàn... Miss, this is the…I have just bought from here. Then I found out…

• 我想换一个。Wǒ xiǎng huàn yīgè. I would like to change another one.

• 一般来说... Yībān lái shuō...Generally speaking...

• 这是我…刚买的 Zhè shì wǒ mǎi dōng xī de. This is the one that I've just bought.

• 这是我买东西的小条儿，当时你也没有…，我也没想到…。Zhè shì wǒ mǎi dōng xī de xiǎo tiáor, dāngshí nǐ yě méiyǒu..., Wǒ yě méi xiǎngdào... This is the receipt for what I bought. At that time, you didn't…, I didn't realize…

• 给您换个…的吧。Gěi nín huàngè…de ba. Should I change a ... one for you?

     E.g. 请给您换个新的吧！

• 那不行… Nà bùxíng ...That's no good...

• 请你把钱退给我。Qǐng nǐ bǎ qián tuì gěi wǒ. Please return me the money.