同意刘老师的解答。为帮助网友理解，我引用《牛津英语语法词典》对 pragmatics（语用学）的解释中的一个例子来说明：

I've borrowed this book from the library.

《牛津英语语法词典》认为这句话在不同情景中有不同的语用功能（交际功能）：

I've borrowed this book from the library, so I don't want to watch TV.

I've borrowed this book from the library, so I don't want to go out.

I've borrowed this book from the library, so I wasn't going to buy it.

……

虽然一般认为“语用学”主要研究语言的实际应用，但《牛津英语语法词典》认为语用学

通常涉及语言的交际功能（it is often used in connection with the communicative functions of language），夸克等人认为“语用学是研究话语的交际意义”（PRAGMATICS is concerned with the communicative force of linguistic utterances）。