How to Write an Essay Introduction (Hook, Context and Thesis)

Key takeaways

• A good introduction has three parts: a hook, short background/context, and a clear thesis statement.
• It should be about 10% of the essay, so roughly 100–150 words for a 1,500-word essay.
• Many strong writers write the introduction last, once they know exactly what the essay argues.

The introduction is the first thing your marker reads, and it shapes how they read everything after it. A clear, confident introduction tells them you know where your argument is going.

The 3-part structure of an introduction

Step 1: Start with a hook

A hook is an opening sentence that makes the reader want to continue. Good academic hooks include:

• A striking statistic: "Nearly one in three adolescents meets the criteria for an anxiety disorder before age 18."
• A surprising fact or contrast: "The country with the world's longest life expectancy also has one of its lowest birth rates."
• A short scenario: useful in reflective, nursing and education essays
• A precise question: use sparingly, and answer it in your thesis

Avoid clichés like "Since the dawn of time…", dictionary definitions ("Webster's defines…") and very broad claims such as "Technology is everywhere."

Step 2: Give background and context

Narrow from the general topic to your specific focus. Tell the reader:

• What the topic is and why it matters now
• Key terms you'll use (define them briefly)
• The debate or problem your essay responds to

Keep it short. Detailed evidence belongs in the body paragraphs.

Step 3: End with your thesis statement

The thesis is the most important sentence in the essay: a specific, arguable claim. For example:

"Although social media helps teenagers stay connected, heavy use harms adolescent mental health by disrupting sleep, encouraging social comparison and exposing users to cyberbullying."

This thesis takes a position and previews three body paragraphs. See our full guide on how to write a thesis statement.

Example introduction

Nearly half of teenagers in the United States say they are online "almost constantly." Social media platforms promise connection, yet rates of adolescent anxiety and depression have risen sharply over the same decade in which smartphones became universal. Researchers still debate whether this is cause or coincidence. This essay argues that heavy social media use harms adolescent mental health by disrupting sleep, encouraging harmful social comparison and exposing young people to cyberbullying.

Hook (statistic) → context (rising anxiety, the debate) → thesis (position plus three reasons).

Introduction template

1. [Hook: statistic, fact or scenario about the topic.]
2. [Why the topic matters today.]
3. [Key context or debate.]
4. [Thesis: your position + the main reasons you'll develop.]

Common mistakes

• Too long: an introduction that takes a full page leaves less room for your argument.
• Announcing instead of arguing: "In this essay I will talk about…" is weaker than stating your claim directly.
• A thesis that is a fact, such as "Social media is popular", which nobody can argue against.
• Evidence and quotes that belong in the body paragraphs.

Frequently asked questions

How long should an essay introduction be?

About 10% of the total word count. For a 1,000-word essay, that's around 100 words; for a 3,000-word essay, 250–300 words, which may be one or two paragraphs.

Should I write the introduction first or last?

Either works, but many writers draft a rough introduction first and rewrite it at the end, once the argument is final. That way the thesis matches what the essay actually says.

Can I use "I" in an introduction?

It depends on the assignment. Reflective essays and personal statements usually expect first person. Most argumentative and research essays use third person, so check your rubric.

Can I start an essay with a question?

Yes, if it's a focused question you answer in the thesis. Avoid vague rhetorical questions like "Have you ever wondered about climate change?"