We are all intimately familiar with at least one language, yet few of us ever stop to consider what we know about it. The words of a language can be listed in a dictionary, but not all the sentences.

　　Speakers use a finite set of rules to produce and understand an infinite set of sentences. These rules comprise the grammar of a language. It includes the sound system and the way in which sounds and meanings are related.

　　This linguistic knowledge is, however, different from linguistic behavior. If you woke up one morning and decided to stop talking, you would still have the knowledge of your language.

　　Language is a tool of communication. But if language is defined merely as a system of communication, then language is not unique to humans. A basic property of human language is its creative aspect.

　　參考答案

　　雖然我們人人至少通曉一門語言，但很少有人會靜心思考一下對語言了解什么。語言的詞匯可以在詞典中列出，但并非所有句子都能為詞典所收入。

　　說話者可以運用一組數量有限的規則來表達與理解數量無限的句子。這些規則組成了語言的語法體系。語法包括音系以及語音和語義之間聯系的規則。

　　然而，語言知識有別于語言行為。某天早晨你醒來后決定不說話，你仍然具有你所操語言的知識。

　　語言是交際的工具。但如果語言的定義僅僅是一種交際系統，那語言便不是人類的專有品。人類語言的一個基本屬性是創造性。