问题：说出至少三种语言的本质特征并解释它们。

本题考查语言的本质特征。

人类语言的本质特征有7个，分别是Productivity多产性，Discreteness离散性，Displacement移位性，Arbitrariness任意性，Culture transmission文化传递性，Duality or double articulation二重性

Interchangeability互换性

Productivity多产性，It refers to the ability that people have in making and comprehending indefinitely large quantities of sentences in their native language，including sentences they never heard before. 人们在造句和理解大量本族语方面的能力，包括未听过的句子；

Discreteness离散性，It refers to the phenomenon that the sounds in a language are meaningfully distinct. 离散性是指语言中的声音具有区分意义的现象；
Displacement移位性，It refers to the fact that human language can be used to talk about things that are present or not present, real or not real, and about matters in the past, present or future, or in faraway places. 人类语言可以用来谈论现在或不现在、真实或不真实的事情，以及过去、现在或未来，或在遥远的地方的事情；

Arbitrariness任意性，Arbitrariness refers to the phenomenon that there is no motivated relationship between a linguistic form and its meaning. 任意性是指语言形式与意义之间没有必然关系的现象；

Culture transmission文化传递性，Language is passed on from one generation to the next through teaching and learning, rather than by inheritance. 语言是通过教与学代代相传的，而不是通过遗传；

Duality or double articulation二重性，Language is a system of two sets of structures, one of sounds and the other of meaning. 语言是由两个结构组成的系统，一个是声音，另一个是意义；

Interchangeability互换性，It means that any human being can be both a producer and a receiver of messages. 任何人都可以既是消息的生产者又是消息的接收者。