Here's the brutal truth: most Band 6 letters don't fail because of bad writing. They fail because the ideas don't connect. Your sentences land like strangers at a party—standing in separate corners with nothing linking them together. The examiner reads through and thinks, "Okay, but why does this sentence follow that one?" That gap between Band 6 and Band 7 is almost entirely about how well your ideas flow and stick together.
The band descriptors spell this out. Band 7 writing shows "clear paragraphing with topic sentences," while Band 6 shows "some paragraphing" that might be fuzzy or all over the place. That's not a small detail. That's the difference between an examiner following your logic and an examiner getting lost halfway through.
I'm going to show you exactly how to spot coherence problems in your own writing and fix them before the examiner ever sees them. This is the same approach that powers our free IELTS writing checker—identifying where paragraphs break down and how to strengthen them.
Coherence is straightforward: it's whether your ideas flow logically. Can the examiner follow your thinking without getting confused or having to backtrack?
Think of it this way. Good coherence means each paragraph builds on the one before it. Each sentence supports the sentence before it. There's an actual reason paragraph B comes after paragraph A, not the other way around. The reader never stops and thinks, "Wait, why are we suddenly talking about this?"
Cohesion is the closely related cousin—it's the actual glue holding everything together. Cohesion includes linking words (like "however" and "therefore"), pronouns, repeated key terms, and connectors. You can have brilliant ideas but terrible cohesion, and your letter will still read like a list of unrelated thoughts.
Tip: The IELTS band descriptors measure "Coherence and Cohesion" as one criterion. You can't separate them. You won't hit Band 7 if one is strong and the other is weak.
Let me show you three real examples of where Band 6 letters break down and how Band 7 writing fixes it. These patterns show up constantly in IELTS writing task 1 letter evaluations.
Weak (Band 6): "I am writing to complain about the noise from your flat. Last week I couldn't sleep. My job interview is next Monday. I need to rest before important events."
See the problem? The writer mentions the noise, jumps to sleeplessness, then throws in a job interview without connecting the dots. The reader has to guess why any of this matters.
Strong (Band 7): "I am writing to complain about the noise from your flat, which has disrupted my sleep for over a week. This has affected my ability to concentrate at work and is particularly concerning as I have an important job interview next Monday. I must rest properly to perform well, and the ongoing disturbances make this impossible."
In the Band 7 version, every idea connects to the next. "Which" ties back to the noise. "This" refers clearly to the sleep disruption. "Particularly" shows how one problem leads to a specific consequence. The final sentence explains what's at stake. No guessing required.
Weak (Band 6): "The kitchen is also too small. I want a bigger apartment. The lease says I can leave after six months. I think I should move to a different building."
This is just a grocery list. Complaint, desire, contract detail, conclusion. Nothing actually connects—they just exist in sequence.
Strong (Band 7): "Another concern is the inadequate kitchen space, which restricts my ability to prepare meals efficiently. Given these ongoing issues, I would like to request either significant improvements to the flat or permission to terminate my lease early. Fortunately, my contract allows me to leave after six months without penalty, so I am prepared to do so if these concerns are not addressed."
Here, the Band 7 version explains why the kitchen matters (it affects daily life). It connects the complaint to a specific request. It references the lease as proof that the request is actually feasible. Everything has a job.
Weak (Band 6): "You promised to fix the heating system by the end of January. The weather has been very cold. I am very unhappy with your service."
The examiner has to connect: broken heating + cold = unhappy. It's all there, but the writer didn't do the work of making that connection explicit.
Strong (Band 7): "Although you promised to repair the heating system by the end of January, it remains non-functional. With temperatures dropping below freezing, the flat is now uninhabitable and poses a health risk. This failure to fulfill your obligation has left me with no choice but to formally request immediate action."
"Although" signals contrast. "With" shows causation. "This failure" ties everything back together and shows consequence. The reader understands exactly why each sentence matters and how they're related.
Most Band 6 letters tank coherence in three specific ways. Once you know them, you can catch these problems in your own drafts and avoid the feedback from an IELTS writing evaluator.
Paragraphs need to follow a logical sequence. For formal complaint letters, it typically goes: greeting, what's wrong, why it matters, what you want done, sign-off. For informal letters: greeting, why you're writing, the main stuff, any follow-up, closing. Jump around, and your letter feels chaotic even if each paragraph is solid on its own.
A Band 6 letter might apologize in paragraph two, explain the situation in paragraph three, then circle back to apologize again in paragraph four. A Band 7 letter gets the order right the first time.
Linking words create the actual glue between sentences. Without them, even logically connected ideas feel disconnected. Look:
Weak: "I paid the full deposit. I have not received a receipt. I am concerned about the security of my payment."
Strong: "I paid the full deposit last month. However, I have still not received a receipt, which concerns me about the security of my payment."
Notice "However" and "which" in the Band 7 version. These aren't fancy—they're clarity tools. They tell the reader, "This next idea contrasts with what came before" or "Here's why that matters."
This goes deeper than just missing linking words. Sometimes two sentences are genuinely unrelated. No linking word can fix that.
Weak: "The room is cold. My salary has not increased in three years."
These ideas have nothing to do with each other. You can't link them because there's no logical relationship.
Strong: "The room is cold due to inadequate heating. As a result, my heating bills have doubled, which is particularly unfair given that my salary has not increased in three years."
Now there's a thread: heating problem, financial consequence, made worse by stagnant income. The ideas actually relate to each other.
You don't need fancy software. Use this five-step process on your own letter.
Tip: For formal complaint letters, these linking words work best: However, Although, Therefore, Consequently, Nevertheless, As a result. Use them deliberately, not randomly.
Here's what actually separates Band 6 and Band 7 in IELTS writing coherence correction: Band 7 writers choose linking words strategically. Band 6 writers throw in words because they sound formal. Band 7 writers pick specific words that show exactly how ideas relate: contrast, consequence, example, similarity, time, or clarification.
Take this real IELTS task:
A local newspaper wants to interview you about an article you've recently written. Write a letter to the editor accepting the interview invitation. In your letter, explain what your article was about, describe your experience as a writer, and say why you'd like to take part in the interview.
Weak (Band 6): "I am grateful for the interview invitation. My article was about climate change. I have been writing for five years. I would like to participate in this interview."
Strong (Band 7): "I am grateful for the interview invitation. My recent article examined the impact of climate change on small farming communities, exploring both the scientific evidence and personal stories from affected regions. As someone who has been writing about environmental issues for five years, I have developed a keen interest in translating complex research into accessible narratives. Therefore, I would welcome the opportunity to discuss the article's findings with your readers and, in doing so, help raise awareness of this important issue."
"Therefore" in the Band 7 version creates cause and effect: because the writer has this experience and interest, they want to participate. It's not fancier vocabulary. It's stronger logic.
Band 7 letters have strong topic sentences. Band 6 letters might have them, but they're weak or vague.
A topic sentence is the first sentence of a paragraph. It tells the reader what the paragraph is about and why it matters. Get your topic sentences right, and coherence almost fixes itself.
Compare these two formal complaint letters:
Weak (Band 6) topic sentence: "There are also issues with the bathroom."
What issues? Why should the landlord care? The reader doesn't know what's coming.
Strong (Band 7) topic sentence: "Beyond the heating problems, I must also address the deteriorating condition of the bathroom, which poses a hygiene risk."
Now the reader knows: this paragraph is about the bathroom, it's bad, and it's a safety issue. Everything that follows supports this single idea.
Tip: Write your topic sentence first. Then check: does every sentence in that paragraph support, explain, or expand that one idea? If a sentence doesn't fit, it belongs somewhere else.
Use this checklist right before you finish. Each point directly affects your Coherence and Cohesion band score.
If you answer yes to all seven, your letter is Band 7 material.
Upload your IELTS Task 1 letter and get instant feedback on coherence, linking words, paragraph flow, and your predicted band score. Our IELTS letter coherence checker shows exactly where your writing stands and what you need to fix to reach Band 7.
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