Using "cai" for small numbers

The character 才 (cái) can be used to emphasize that a number is small, or less than expected.

Structure

才 (+ Verb) + Number + [Measure Word] + Noun

In English, we often express this by using "only" or "just" to emphasize that the number is small.

你才二十岁？Nǐ cái èrshí suì?You're only twenty?
你才吃了一个？Nǐ cái chī le yī gè? You only ate one?
这个班才两个学生。 Zhège bān cái liǎng gè xuéshēng.This class only has two students.
你的工资才两千？Nǐ de gōngzī cái liǎng qiān?Your salary is only two thousand RMB?
她才来上海两个月。Tā cái lái Shànghǎi liǎng gè yuè.She's only been in Shanghai for two months.
这顿饭才花了二十块。Zhè dùn fàn cái huā le èrshí kuài.This meal only cost twenty kuai.
你才一百斤，还说要减肥？One "jin" = 500gNǐ cái yī bǎi jīn, hái shuō yào jiǎnféi?You're only 100 jin and you're talking about losing weight?
这家店关门了？可是它开业才一个星期。Zhè jiā diàn guānmén le? Kěshì tā kāiyè cái yī gè xīngqī.This shop is out of business? But it's only been one week since it opened.
我才玩一会儿，让我再玩一会儿吧？Wǒ cái wán yīhuìr, ràng wǒ zài wán yīhuìr ba?I only played for a short while. Can I play a little bit longer?
他们结婚了？可是他们认识才三个月！Tāmen jiéhūn le? Kěshì tāmen rènshi cái sān gè yuè!They got married? They've only knew each other for three months!