IELTS Punctuation: Commas and Full Stops for a Band 7.0+

When preparing for IELTS Writing Task 1 and Task 2, candidates spend hundreds of hours memorizing complex vocabulary and advanced grammar structures. Yet, they often overlook the smallest marks on the page: punctuation.

Under the IELTS grading criteria for Grammatical Range and Accuracy, punctuation is explicitly evaluated. If you write brilliant, high-level sentences but fail to use full stops and commas correctly, your writing becomes chaotic. Examiners call this a lack of “control,” and it can instantly trap your score at a Band 5.5 or 6.0.

Punctuation is the traffic light system of your essay. It tells the examiner when to slow down, when to pause, and when a complete thought has finished. This guide breaks down the absolute rules of commas and full stops, and how to avoid the deadly “comma splice” trap.

The Full Stop (.) – The Boundary Maker

The full stop (or period) has one job: to mark the absolute end of a complete thought (an independent clause).

A complete thought must contain a Subject and a Verb, and it must make logical sense on its own. The biggest mistake candidates make is writing sentences that are far too long, resulting in the dreaded “Run-On Sentence.”

The Run-On Sentence Trap

When you try to impress the examiner by linking too many ideas together without a full stop, the grammar collapses.

The Error: The government should invest heavily in public transport it is the only way to reduce carbon emissions in major cities the current infrastructure is failing.
The Fix: Use full stops to create clear, powerful boundaries.
Band 7.0+ Version: The government should invest heavily in public transport. It is the only way to reduce carbon emissions in major cities, as the current infrastructure is failing.

Golden Rule for Full Stops: If you read your sentence out loud and you run out of breath before reaching the end, you need a full stop. Aim for an average sentence length of 15 to 25 words.

The Comma (,) – The Breathing Space

Commas are the most misused punctuation marks in the IELTS exam. Candidates either use too many (sprinkling them everywhere like salt) or none at all.

To achieve a high score, you must stop guessing and start applying these four strict mathematical rules.

Rule 1: The Transition Word Comma

In IELTS Writing, you will use signposting words to connect your ideas. If these words appear at the beginning of a sentence, they must be followed by a comma.

Incorrect: Therefore the solution is obvious.
Correct: Therefore, the solution is obvious.
Common Transition Words: However, Furthermore, In addition, Consequently, Firstly, Ultimately.

Rule 2: The “FANBOYS” Comma (Compound Sentences)

When you connect two complete, independent sentences using a coordinating conjunction (For, And, Nor, But, Or, Yet, So), you must put a comma before the conjunction.

Incorrect: Tourism brings money to the economy but it damages the local environment.
Correct: Tourism brings money to the economy**, but** it damages the local environment.

Rule 3: The Complex Sentence Swap

Complex sentences use subordinating conjunctions (Because, Although, If, While, Since). The comma rule depends entirely on the order of the sentence.

Condition A (Conjunction First): If the sentence starts with the conjunction, put a comma in the middle.
- Example: Although electric cars are expensive**,** they are better for the environment.
Condition B (Conjunction in the Middle): If the conjunction is in the middle, do not use a comma.
- Example: Electric cars are better for the environment although they are expensive.

Rule 4: The “Extra Information” Comma (Non-Defining Relative Clauses)

If you add extra, non-essential information into the middle of a sentence, you must trap that information between two commas. If you remove the words between the commas, the sentence should still make perfect sense.

Example: The internet**, which was invented in the 20th century,** has completely changed how we communicate.

The #1 Fatal Error: The Comma Splice

If you only remember one thing from this guide, make it this. The Comma Splice is the most severely penalized punctuation error in IELTS Writing.

A comma splice happens when you try to connect two complete, independent sentences using only a comma. A comma is not strong enough to glue two full sentences together.

The Comma Splice (Band 5.0): Many students study abroad*,** they want to learn a new language.* Notice how “Many students study abroad” and “they want to learn a new language” are both complete sentences? A comma cannot hold them.

How to Fix a Comma Splice (3 Options):

Use a Full Stop: Many students study abroad. They want to learn a new language.
Use a FANBOYS Conjunction: Many students study abroad*, for** they want to learn a new language.*
Use a Subordinating Conjunction: Many students study abroad because they want to learn a new language.

Quick Proofreading Checklist for Exam Day

Save 3 minutes at the end of your Writing Task 1 and Task 2 to scan exclusively for punctuation errors. Look for these visual cues:

What to Scan For	The Question to Ask Yourself
Capital Letters	Did I put a full stop right before this capital letter?
Linking Words	Did I put a comma immediately after However, Therefore, and Furthermore?
Middle Commas	Is the comma holding two full sentences together? (If yes, fix the comma splice!).
Sentence Length	Does this sentence take up more than three lines of paper? (If yes, break it up with a full stop).