Supermarket

些 (xiē) for Plural
In English, we add ‑s to mean more than one thing (for example, apples or books). But in Chinese, it’s not always necessary to show that something is plural.

In the example below, it doesn’t matter if we’re referring to
one watermelon or multiple watermelons: It will be clear to a Chinese speaker that you’re asking about the price of watermelons in general.
西瓜多少钱
(Xīguā duōshǎo qián?) How much is watermelon?
However, you'd need to add 这些 (zhèxiē) to show that you're talking about specific (plural) watermelons.
这些西瓜多少钱
(Zhèxiē xīguā duōshǎo qián?) How much are these watermelons?
Here are a few more words you can use to show that you’re talking about more than one thing.
singularplural

(yī), one
一些
(yìxiē), some

(zhè), this
这些
(zhèxiē), these

(nà), that
那些
(nàxiē), those
我想买一些苹果。
(Wǒ xiǎng mǎi yìxiē píngguǒ.) I want to buy some apples.
那些鸡蛋不好。
(Nàxiē jīdàn bù hǎo.) Those eggs are not good.