An impromptu essay is one that you have to write immediately after you get the essay subject matter. This usually is a timed assignment that forces you to think quickly and to articulate your thoughts, working with a specific deadline. The person grading your essay will assess your writing skills by examining your use of grammar, punctuation and spelling, as well as your thought process and the way your essay flows from beginning to end.

Introduction

When writing an impromptu essay, first carefully read the question topic on which you are writing the essay and spend a moment contemplating how you will answer it. Then create a brief outline -- even if you do this in the margin of your impromptu writing paper -- and mention how you plan to introduce your essay, the three points on which you want to expand and then how you wish to conclude the writing prompt.

Start your essay out with a striking statement or descriptive anecdote. For instance, if writing an impromptu essay about wanting to become a doctor, explain that you initially never even imagined being able to go to college.

Thesis and Body

The impromptu essay should have a distinct thesis statement -- a statement that highlights the theme of your essay in about one sentence. Support this thesis statement by explaining three points of your impromptu essay in the essay's body. Your three points should be detailed, provide clear examples and make sense with your thesis. For example, if you are writing an impromptu essay on why school food items should be healthier, explain as one of your points that junk foods contribute to obesity and give examples from your experience as to why this can be detrimental.

Other Body Information

In your impromptu essay, do not worry about including specific details such as dates or years from any reference materials you cite in your essay if you simply cannot remember them. Just elaborate on the concepts, and try to include reputable sources for your points. Include the keywords from the impromptu essay assignment question throughout your essay to show the person grading the essay that you were able to stay on topic. Also, introduce each paragraph in the essay body with words such as "first," "second" and "third" so that your explanations can flow logically and your transitions are evident.

Conclusion

Finish your essay by briefly reiterating your thesis and the points you made in the essay, then tying it all together with a clear conclusion. Try to pace yourself to have at least five minutes remaining before the time is up, so that you can read through the essay to see if you can reword certain phrases or need to change any spelling or grammatical errors.