The Grammar Mistakes IELTS Examiners Hear Most in Speaking (and Why You Keep Making Them)

The grammar mistakes examiners hear most in IELTS Speaking are not rare or advanced ones — they are small, repeated errors: missing or wrong articles (a/the), a dropped third-person -s, tenses that drift while telling a story, wrong prepositions after common verbs, and second and third conditionals mixed together. What makes them costly is not the mistake itself — everyone makes slips, including native speakers — it is that for many candidates the same mistake shows up in nearly every response. That pattern has a name: a fossilized error, a mistake that has become automatic through repetition, so the speaker no longer notices it and cannot self-correct without outside help.

What is a fossilized error

A fossilized error is a mistake that has been repeated so many times it has become part of how you automatically produce English, rather than something you actively choose. The term comes from language acquisition research, but the practical definition for IELTS is simple: it is the mistake that shows up in your third sentence, your seventh sentence, and your fifteenth sentence, in more or less the same form, regardless of topic. A slip is something you say once and could correct if someone pointed it out mid-sentence. A fossilized error is something you would probably say the same way even if someone pointed it out, because it does not register as wrong to you in the moment. It tends to show up most clearly in a longer, unscripted response, such as the two-minute Part 2 long turn, simply because there are more sentences in which it can repeat.

Why do fossilized errors form

Early habits that were never corrected

Most fossilized errors start early, often in a classroom where speaking practice was limited and a teacher did not have time to correct every sentence. A mistake repeated without correction for months or years stops feeling like a mistake.

First-language interference

Many of the most common patterns come directly from how a learner’s first language handles the same idea. A language without articles produces a learner who has to consciously decide when English needs “a,” “the,” or nothing at all — and under exam pressure, conscious decisions are the first thing to drop.

Never getting real feedback on spoken English

Written grammar gets corrected in essays and homework. Spoken grammar, for a lot of learners, almost never does — conversations move on before an error can be flagged, so the same pattern gets to repeat indefinitely without anyone stopping it.

Why fossilized errors cap your grammar score

The public IELTS Speaking band descriptors — the official wording examiners use to describe what performance at each band level sounds like, for each of the four criteria — for Grammatical Range and Accuracy describe Band 7 as using a range of complex structures with some flexibility, and frequently producing error-free sentences, though some grammatical mistakes persist. Band 6, by contrast, is described as using a mix of simple and complex forms, with frequent mistakes in the complex ones, though these rarely prevent the listener from understanding.

Read those two descriptions side by side and the ceiling becomes clear: “frequently error-free” at Band 7 is only an accurate description if your mistakes are occasional and varied. A fossilized error, by definition, appears in nearly every response — which means “frequently error-free” simply does not describe that speech, no matter how sophisticated the vocabulary around it is. This is why a candidate can have genuinely strong ideas and a wide vocabulary and still sit at Band 6 for grammar: one repeated pattern, not a general lack of ability, is doing the damage.

Why self-study usually cannot find these errors

This is the frustrating part: you cannot hear what you cannot hear. A fossilized error does not sound wrong to the person producing it, which is exactly why it survived long enough to fossilize in the first place. Reading a grammar book and recognising the rule “he goes, not he go” does not reliably transfer to noticing yourself doing it live, under time pressure, while also thinking about content and vocabulary.

What actually works is a recording plus a system that tracks patterns across multiple sessions rather than a single one-off correction. A single lesson where a teacher corrects “he go” once is easy to forget by the next class. Seeing the same correction flagged across five separate recordings, on five different topics, is much harder to ignore — that is the whole logic behind apps like IELTS Mentor AI, which record your answers and track whether the same error keeps recurring across sessions rather than treating each recording as a one-off.

The most common grammar mistakes in IELTS Speaking

Articles: a/the with countable nouns

This is the classic fossilized error for speakers of Russian, Uzbek, Chinese, Japanese, and Korean, among other languages, because none of these languages use articles the way English does, so the choice never becomes intuitive without deliberate practice.

• Wrong: “I have interview next week for job at bank.”
• Right: “I have an interview next week for a job at a bank.”

Tense consistency when narrating

Part 2 answers are often narratives, and narratives need the past tense to stay consistent unless you deliberately shift to the present for effect.

• Wrong: “Last summer I go to my grandmother’s village and we spend two weeks there.”
• Right: “Last summer I went to my grandmother’s village and we spent two weeks there.”

Subject-verb agreement with third-person -s

• Wrong: “My sister work in a hospital and she help many patients every day.”
• Right: “My sister works in a hospital and she helps many patients every day.”

Prepositions after common verbs

• Wrong: “It depends of the weather.” / “We arrived to the airport early.” / “We discussed about the plan.”
• Right: “It depends on the weather.” / “We arrived at the airport early.” / “We discussed the plan” (no preposition needed here).

Conditionals: second vs third

• Wrong: “If I would have more time, I will travel more.” (mixing forms from two different conditional structures)
• Right, second conditional, for an unreal present situation: “If I had more time, I would travel more.”
• Right, third conditional, for an unreal past situation: “If I had had more time last year, I would have travelled more.”

Countable and uncountable nouns

• Wrong: “She gave me some advices about the furnitures I need for my new informations.”
• Right: “She gave me some advice about the furniture I need,” and “I found some useful information.”

Overusing “very” and “good” instead of precise vocabulary

This one sits slightly outside grammar — it is a Lexical Resource issue, not Grammatical Range and Accuracy — but it is worth flagging here because it often travels together with the errors above. Saying “very good,” “very interesting,” and “very nice” repeatedly, instead of words like “impressive,” “fascinating,” or “considerate,” caps your vocabulary score even when your grammar is accurate. How Band 6 and Band 7 actually differ across all four criteria, including this exact issue, is covered in more detail separately.

A three-step routine to find and fix your own fossilized error

1. Record three minutes of unscripted speaking. Answer two or three practice questions out loud and record yourself, without stopping to correct anything as you go.
2. Transcribe it, even roughly. Write out what you actually said, not what you meant to say. This step is where most self-study breaks down, because it is tedious — but transcribing forces you to notice mistakes your ear skipped over while speaking.
3. Tally the errors by category and drill only the most frequent one. Count how many times each type from the catalogue above appears. Whichever category has the highest count is your fossilized error. Drill that one specifically for a week before moving to the next — trying to fix five categories at once usually fixes none of them.

Grammar in Speaking is not scored on whether you know advanced structures. It is scored on whether your everyday sentences hold up under repetition. Finding the one pattern that repeats across your own speech, and drilling it deliberately, moves the needle far more than general grammar revision, because it is the repetition, not the mistake itself, that was capping the score.