The purpose of an introduction

Why is it that many students find it so difficult to write the opening few sentences or paragraphs of an essay? The simple answer to this question is that being able to write a good introduction is actually something of a craft. Most of us have been told at school how important it is to get an essay off to a good start with a powerful introduction, yet the writing of many undergraduate students suggests that in practice this means little more than a statement of intent, a brief summary of what they're going to discuss in the essay. In reality, an introduction needs to do far more than this. Once you know more precisely what an introduction is, what it seeks to achieve and how it can most effectively be made to serve its purpose, you'll be able to craft far more effective introductions, and with greater ease.

Essentially, an introduction frames the discussion that's to come in the body of your essay; it prepares the reader by providing a context – reference points or hooks – that helps them to engage better with that discussion. That context is usually created by making reference to the relevant literature and/or by discussing a problem or observation that has arisen as a result of your or somebody else's experience (of language use, language learning or language teaching, for example). Once a context has been established, it needs to be made clear to the reader what you plan to discuss in your essay and how it fits into that context.