How should I structure my introduction for an English literature essay?

A good place to start from when planning or writing any essay is to imagine what it might look like at the end, and the same goes for writing your introduction. A good introduction should start by introducing the reader to the world of the text or issue at the heart of the essay, so that they can understand your analysis and arguments from the beginning. For example, if you are writing an essay on the significance of ghosts or the supernatural in 'Hamlet', you might start by explaining that the supernatural features widely in Shakespeare's plays, linking 'Hamlet' to other plays which make use of this feature, but specifying that 'Hamlet' is particularly famous for its use of ghostliness. (Usually, one or two sentences will be more than enough to achieve this.) After a general insight into the topic, it is useful to then introduce the specific argument you are making in the essay: "In 'Hamlet'," to continue the above example, you might suggest that "the supernatural plays a significant role in our understanding of [character]/[theme]." (If the title of the essay is framed as a question, state your overall answer by referring to some of the key terms used by the question.) Once you have outlined the argument you intend to make, be sure to then describe how you are going to make this argument. Identify the areas you will be focusing on in your analysis, such as particular characters, events, themes, chapters/scenes, lines, etc. Briefly describe why you have chosen those examples for your analysis, and how they will support your argument. (It helps to identify any secondary reading / critical literature you are using here, if applicable!) After you have set out the path forward for your reader, you should finish by suggesting where their reading experience through your writing should take them: your conclusion. If you can end the introduction by suggesting what you ultimately want the reader to learn or understand from your essay, this will help guide them through your analysis and understand your argument more easily--especially helpful if your reader is also your teacher, or an examiner! (Plus, an introduction which begins with the end in mind should help you to keep focused while you write the rest of your essay, and so a good introduction will benefit everyone involved!)