Linguistics is the scientific study of language. Its branches include grammar, phonetics and phonology, psycholinguistics, sociolinguistics, neurolinguistics, stylistics, semantics, historical linguistics, computational linguistics, etymology, semantics and pragmatics. Like other scientists, linguists have intuitions about particular aspects of their subject, and they try to find out if they’re right through rigorous observation and deduction.
The practical benefits of some academic disciplines are more obvious than others. Medicine, engineering, and law faculties, to take just three, all produce people who are indispensable to modern society. But practical benefits are by-products, if, as in the case of these three, indispensable by-products, of the pursuit of knowledge. The prime motivation for extending and disseminating knowledge is not getting a good job, or even improving the world, desirable though both may be. Finding out about things is simply what humans do, and to limit such activity is to diminish humanity. The quotation attributed to the mountaineer George Mallory on being asked why he wanted to climb Everest applies to most human endeavour, including academic endeavour: ‘Because it’s there.’
All that has to be said, but, in practice, it is rare that academic study has no practical benefits, even if they are not its primary aim, and that’s true of linguistics as much as anything else. It is obviously of direct relevance in a field such as lexicography, but linguistics can also be applied to socially beneficial areas such as forensics and the treatment of various kinds of speech impairment. More widely, knowing how language works is an asset to those engaged in politics, journalism, advertising and the teaching of English and foreign languages.
For all of us, some knowledge of what is arguably the most important distinguishing feature of the human species is valuable. It allows us to be critical of our own use of language and that of others, particularly of those who are trying to persuade us to do something we would rather not. And it’s fascinating as a subject in its own right. Such knowledge, however, is no more easily acquired than knowledge of chemistry, law or history. If you’re new to the subject, you can make a start with some of the sources I provide under References.