这 / 那 + 量词
zhè / nà + liàng cí
Measure words with "this" and "that"
这 and 那 need a measure word too, exactly as numbers do.
这 / 那 + Measure Word (+ Noun)
How it works
这个人, 那本书, 这杯水. You cannot say 这人 in neutral speech — the measure word is required.
A number can sit between: 这三本书 (these three books). And with the noun understood, 这个 alone works: 我要这个.
The plural forms are 这些 and 那些, which take no measure word.
Examples
nà ge rén shì shéi?
那个人是谁？
Who's that person?
zhè bēi shuǐ shì nǐ de
这杯水是你的。
This glass of water is yours.
zhè sān běn shū dōu hěn hǎo
这三本书都很好。
These three books are all good.