10 Essay Writing Mistakes That Cost You Marks

Markers grade hundreds of essays a year, and certain mistakes show up so consistently that they are almost predictable. Most of them are not about knowledge or ideas - they are about execution. Here are the ten that cost students the most marks, and what to do instead.

1. A Thesis Statement That Is Too Broad

"This essay will discuss the effects of climate change" is a topic, not an argument. A thesis statement needs to take a specific, arguable position that the rest of the essay then defends. Compare it to: "Climate change disproportionately affects low-income coastal communities because adaptation infrastructure is unevenly funded." The second version gives the essay something specific to prove.

Fix: Before you write your introduction, write your thesis as a single sentence that someone could reasonably disagree with. If no one could disagree with it, it is not yet a thesis.

2. Answering a Different Question Than the One Asked

This is more common than it sounds, especially under time pressure. A student prepares strong knowledge on a topic, then writes the essay they were ready to write rather than the essay the question actually asked for.

Fix: Underline the command word (analyse, evaluate, compare, discuss) and the specific focus of the question before you start. Refer back to the exact wording periodically as you write.

3. Paragraphs Without a Clear Topic Sentence

A paragraph that opens with an example or a quote, rather than a claim, forces the reader to work out the paragraph's point themselves. Every paragraph should open with a sentence that states its argument.

Fix: Write your paragraph's topic sentence first, as a standalone claim. Then build the evidence and explanation underneath it.

4. Evidence Without Explanation

Dropping in a quote or statistic and moving on, without explaining what it shows and why it matters to your argument, is one of the fastest ways to lose analysis marks. Evidence does not speak for itself.

Fix: After every piece of evidence, add at least one sentence explaining specifically how it supports your point - not just that it is relevant, but how.

5. Overusing Quotations Instead of Analysis

Essays with long strings of quoted material, connected by minimal original commentary, read as under-analysed even when the quotes are well-chosen. Markers are grading your thinking, not your ability to select quotes.

Fix: As a rough guide, your own analysis should significantly outweigh quoted material in any paragraph. If a quote can be paraphrased without losing precision, paraphrase it.

6. Weak or Repetitive Transitions

Essays that rely on "firstly, secondly, thirdly, finally" throughout read as a list rather than an argument. See our companion piece on essay transitions and flow for a full breakdown of how to fix this.

Fix: Vary your transitions to reflect the actual logical relationship between paragraphs - building, contrasting, or showing consequence - rather than defaulting to sequence words.

7. Ignoring Counterarguments

An essay that only presents evidence supporting its own position, without acknowledging the strongest opposing view, often reads as one-sided rather than well-reasoned, even when the core argument is correct.

Fix: Include at least one paragraph that fairly presents a counterargument before explaining why your position still holds. This usually strengthens your argument rather than weakening it.

8. Inconsistent Tense or Voice

Switching between past and present tense, or between formal and informal register, partway through an essay is a small thing individually but adds up to a less polished, harder-to-follow piece of writing.

Fix: Decide on a tense (usually present tense for literary analysis, past tense for historical or experimental discussion) and register before you start, and check consistency in your final read-through.

9. A Conclusion That Just Repeats the Introduction

Restating your introduction almost word-for-word signals that your thinking has not developed across the essay, even if it genuinely has. See our companion piece on writing a strong conclusion for the full fix.

Fix: Your conclusion should synthesise how your points connect, not summarise them in the order you wrote them.

10. Not Leaving Time to Proofread

Even strong essays lose marks to typos, missing words, and formatting inconsistencies when they are submitted straight after the final sentence is written. A tired brain reading its own writing tends to see what it meant to write, not what is actually on the page.

Fix: Leave at least a few hours, ideally a full day, between finishing a draft and proofreading it. Reading it aloud, or having someone else read it, catches errors your own eyes will skip past.

Why These Mistakes Persist Even in Strong Students

Most of these mistakes are not knowledge gaps - they are habits formed under time pressure, when the priority shifts to finishing rather than refining. A student who fully understands the difference between summarising and synthesising in theory will still write a repetitive conclusion at 2am before a deadline, simply because there is no time left to notice it. This is precisely why a second read, ideally with a gap of at least a few hours after finishing a draft, catches so many of these issues that the writer genuinely knows how to fix but did not have the distance to see in the moment.

Turning This Into a Pre-Submission Checklist

Before you submit, run through this list specifically:

• Is my thesis a specific, arguable claim?
• Does every paragraph answer the actual question asked?
• Does every paragraph open with a topic sentence stating its claim?
• Is every piece of evidence followed by explanation, not left to speak for itself?
• Have I addressed at least one counterargument?
• Is my tense and register consistent throughout?
• Does my conclusion synthesise rather than repeat?
• Have I proofread with fresh eyes, not immediately after writing?

If you would rather have someone else check an essay against this list before you submit it, CampusScribe's editors review essays specifically for these structural and argumentative issues, not just spelling and grammar - catching the kind of mistakes that are hardest to see in your own writing.

From choosing a topic to polishing a final draft, CampusScribe's subject-specialist editors and coaches help with dissertations, capstone projects, presentations, and more - whether you need topic guidance, structural feedback, or a final edit before your deadline.