Beyond counting: the curious number 2 (Elementary)

What exactly do you know about the number 2? Is it just a mere number in Mandarin? Let’s have a look at the following conversation and see just where you stand.

             Nǐ tài èr le. Lǐ Huá:你 太 2 了。

              Á?   Lucy:啊?

             Nǐ de chēpáishang …