How do I write a good English Language essay?

The first point to consider is what type of essay you are being asked to write. Is it a persuasive or argumentative essay? Do you need to express your own opinion?
It is a good idea to spend some time planning the essay and making short notes, perhaps just key points, and think about how best to structure your paragraphs. Remember that each paragraph must have one distinct point and this point should not be discussed in other paragraphs. Each paragraph should lead into the next in a fluid way that leaves no room for the reader to become confused. The arguments should logically lead from one idea to the next.
The introduction and conclusion can often be written last. This is because the introduction introduces the main point in each paragraph and the conclusion summarises the main point in each paragraph. They are in fact, very similar. Both the introduction and conclusion present the essay to the reader and the conclusion does not provide any additional or new information.
Your essay should be between 4 and 5 paragraphs long - so 2 to 3 main ideas and an introduction and conclusion.