Here's something that might surprise you: about 30% of IELTS writing submissions contain subject-verb agreement errors. The kicker? They're completely preventable. This isn't about being pedantic. The IELTS Grammatical Range & Accuracy band descriptor explicitly penalizes sentences with "errors in agreement." One misplaced verb can drop you from Band 7 to Band 6.5 on the writing section alone.
You probably know the basic rule already. Singular subject, singular verb. Plural subject, plural verb. But IELTS test makers are sneaky. They love hiding tricky subjects in complex sentences, and that's exactly where most students slip up. These common grammar errors are what separates Band 6 writers from Band 7 writers.
Let me walk you through the exact spots where most people mess up, and more importantly, how to catch these errors before you hit submit.
This is the biggest culprit. You read a sentence, spot what looks like the main subject, match it with a verb, and then move on. But the real subject is somewhere else entirely, and you've chosen the wrong verb form.
Take this example:
Weak: "A series of studies on climate change have revealed alarming trends."
What's the actual subject here? It's "series," not "studies." The phrase "of studies" is just a prepositional phrase modifying "series." Since "series" is singular, you need "has," not "have."
Good: "A series of studies on climate change has revealed alarming trends."
This pattern shows up constantly in IELTS essays:
That last one trips everyone up. With "a number of," the real subject becomes plural, so you need a plural verb.
Weak: "A number of factors has contributed to rising unemployment."
Good: "A number of factors have contributed to rising unemployment."
When two subjects are connected by "or" or "either...or," the verb agrees with whichever subject is closest to it. This rule feels counterintuitive at first, but it's consistent.
Good: "Either the manager or the employees are responsible."
Good: "Either the employees or the manager is responsible."
Notice the order changed the meaning? In the first sentence, you're saying the employees are responsible. In the second, it's the manager. That's not accidental, it's intentional, and it matters which subject lands closest to the verb.
Weak: "Either the students or the teacher have graded the papers." ("teacher" is closest and singular, so use "has")
Good: "Either the students or the teacher has graded the papers."
Collective nouns describe groups acting as a single unit: team, committee, audience, government, family, company.
In American English (which IELTS follows), these are singular. One team, one decision, one action.
Good: "The team is preparing for the championship."
But here's the twist. If you're emphasizing conflict or disagreement between individuals in that group, you can switch to plural:
Good: "The team are divided on strategy."
For IELTS writing tasks, stick with singular unless you're explicitly showing tension or disagreement among members. Examiners expect consistency, and singular is the safer default.
Quick check: Replace the collective noun with "it" in your head. "It is preparing" sounds right (singular). "It are divided" sounds off, so only use plural if you're really emphasizing disagreement.
Most English sentences follow Subject-Verb-Object order. But some structures flip this, and that's where you lose track of what the real subject is.
Here's a question: what's the subject in "In the city center are located three museums"?
It's "three museums," not "city center." So even though the verb appears first, it still needs to be plural. Finding the subject in inverted sentences is crucial for IELTS grammar accuracy.
Weak: "In the research facility exists many laboratories dedicated to pharmaceutical innovation."
Good: "In the research facility exist many laboratories dedicated to pharmaceutical innovation."
The trick is mental rearrangement. "There are three reasons" really means "three reasons are there." So you check agreement with "reasons," not "there."
Words like "everyone," "nobody," "someone," "anybody," and "each" are grammatically singular. Even though they refer to multiple people, you use singular verbs.
Weak: "Everyone are entitled to fair treatment under the law."
Good: "Everyone is entitled to fair treatment under the law."
This applies to "anyone," "somebody," "nobody," "either," "neither," and "each" when they stand alone. Band 6 writers miss these regularly. Band 7 writers catch them every time.
Pro tip: Mentally replace the indefinite pronoun with "he" or "she." If it works ("He is entitled"), use singular. Takes one second and saves you points.
When you write a relative clause using "who," "which," or "that," the verb inside that clause must agree with the noun it's modifying. Not the main sentence's subject. The noun the clause is actually describing.
Weak: "This is one of the policies that has had significant impact."
Good: "This is one of the policies that have had significant impact."
The relative clause modifies "policies" (plural), so you need "have," not "has." Your brain wants to match it with "this" from the main clause, but that's the error.
Another common variation:
Weak: "The only policy that address this issue is outdated."
Good: "The only policy that addresses this issue is outdated."
"Policy" is singular, so "addresses" is correct. When you're building relative clauses in your IELTS essay writing, this kind of precision directly impacts your Grammatical Range & Accuracy band.
When you write about amounts, the verb agrees with the number itself, not what's being measured.
Good: "Fifty percent of the population lives in urban areas."
Good: "Two kilometers is a reasonable distance."
But when the plural items are what you're emphasizing:
Good: "Five thousand people have been displaced."
The pattern: if the number or amount is your focus, use singular. If you're emphasizing the counted items, use plural. In IELTS Task 1 and Task 2 writing, you'll usually see the singular construction, especially when discussing data or measurements.
You won't memorize every rule perfectly. But you can develop a system that catches these errors during your final read-through. This is what Band 7 writers do consistently.
Step 1: Find every verb. Don't just skim. Highlight (mentally) every single verb in your essay.
Step 2: Identify the subject. For each verb, draw a line back to its subject. Don't guess. Verify.
Step 3: Determine singular or plural. Ask yourself: is the actual subject singular or plural? Use the rules above if it's tricky.
Step 4: Match them up. Does the verb form match the subject? If not, fix it.
This takes about 3 minutes for a 250-word Task 1 essay or a 350-word Task 2 response. That's 3 minutes that could move you from Band 6.5 to Band 7 in Grammatical Range & Accuracy.
Reality check: After 1 hour in the IELTS writing exam, you'll be tired. Subject-verb agreement errors spike when you're exhausted. That's exactly why proofreading beats perfect first drafts. You're not aiming for perfection, you're catching mistakes under pressure.
If you're working on broader grammar foundations, conditional sentences and passive voice timing are equally important for reaching Band 7. But subject-verb agreement is the fastest win because it's the most visible error to examiners. Try submitting an essay for detailed grammar feedback to see exactly where your agreement errors appear.
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