Why does an IELTS examiner coach the Duolingo English Test (DET)?

High-proficiency English is assessed using the same core criteria (fluency, coherence, lexical and grammatical range) whether by a human examiner (IELTS) or an AI algorithm (DET). Teacher Leda applies her insider knowledge of these rigorous standards to teach the specific features the DET algorithm rewards.

What is the 'Complexity Wall' (Band 7 / Score 120)?

The 'Complexity Wall' refers to the score cap placed on students who speak or write clearly but only use simple grammar. To break past DET Score 105/110 and reach 120+, students must actively demonstrate C1-level grammatical range, such as conditional and subordinate clauses.

How does the DET AI penalize memorized answers?

The Duolingo AI is designed to detect unnatural phrasing, vocabulary density mismatches, or a lack of spontaneous speech, which suggests memorization. This can lead to the test being flagged as invalid by human proctors.

The Ex-Examiner Advantage

How My 12 Years Assessing IELTS for the British Council
Helps You Master the Duolingo English Test

Why an IELTS Examiner is Your Best Weapon for DET

You might be wondering: “If I’m taking the Duolingo English Test (DET), why does it matter that Leda was an IELTS examiner?”

The answer is simple: High-proficiency English looks the same, whether a human or a computer marks it.

The Duolingo algorithm is trained on the same standards of fluency, coherence, and grammatical range that I used to assess 6,000+ students. The difference is, most DET tutors are just “native speakers.” I am a trained assessor. I know exactly why a sentence gets a C1 score versus a B2 score.

What I Learned in My First Week as an Examiner

October 2013. Bangkok, Thailand. British Council Training Center. I thought I knew English teaching. Then I went through examiner training.

The Revelation: We watched the same Speaking test video 15 times. The trainer didn’t care about “good ideas.” He asked: “Did you hear the subordinate clause? Did you notice the lack of connected speech?”

I realized that examiners (and now AI algorithms) don’t listen like normal people. They listen for SPECIFIC DATA POINTS. They check boxes for lexical resource, grammatical range, and coherence markers.

Applying This to Duolingo: When I teach DET, I don’t just “chat” with you. I am constantly assessing you against those same rigorous standards. I can hear the invisible mistakes that the AI will penalize, mistakes that regular tutors completely miss.

What Examiners Know That Students (and Apps) Don’t

Insight #1: The “First 30 Seconds Rule”

In IELTS, I formed 60% of my score in the first minute. In DET “Speaking about the Photo,” you only HAVE 30-90 seconds. You must demonstrate high-level features immediately.

What This Means For You: You cannot “warm up.” You need to hit the ground running with complex structures.

What I Teach: The specific “Opening Structures” that instantly signal to the AI (or examiner) that you are a Band 7+ / Score 120+ candidate.

Insight #2: The “Complexity Wall” (Band 7 / Score 120)

Many students speak clearly but use simple grammar. In my examiner training, this was the classic “Band 6 Trap.” To get Band 7+ (or DET 120+), you MUST demonstrate range.

Band 6 / DET 105: “I like travel. It is fun. I go with friends.” (Correct but Simple)

Band 7+ / DET 125+: “Although travel can be expensive, I find the experience invaluable, particularly when accompanied by friends.”

What I Teach: The specific grammatical structures that define “Advanced English” in assessment criteria, ensuring you break the complexity wall.

Insight #3: “Natural English” vs. “Robot English”

Ironically, trying to sound “smart” often lowers your score. Examiners (and the DET AI) look for natural collocations. If you say “do a crime” instead of “commit a crime,” you lose points.

What I Teach: I use my ear as an examiner to catch unnatural phrasing that sounds “translated,” helping you sound like a native speaker to the grading algorithm.

Insight #4: The Memorization Penalty

In IELTS, if I suspected a memorized script, I had to penalize the student. The Duolingo AI is even stricter, it will flag your test as invalid. I can spot a memorized answer in 5 seconds.

Memorized Script: “This is a wonderful picture that depicts many interesting aspects of society…”

Natural Response: “This image captures a chaotic scene in a busy market…”

What I Teach: How to use “Flexible Frameworks” that provide structure without triggering the “memorization penalty” from the AI or human proctors.

Insight #5: Systematic Errors

Examiners forgive slips. We do NOT forgive “systematic errors” (making the same grammar mistake repeatedly). This is the fastest way to lower your Production Score.

What I Teach: I diagnose your specific recurring errors, which are the ones you don’t even know you’re making, and fix them permanently.

The SCORE Framework: Universal Assessment Standards

Whether you are taking IELTS or DET, the criteria for high scores remain the same. I use the SCORE Framework to ensure you satisfy the marking criteria.

Specific Examples

Moving from generic statements to specific details (Crucial for DET Photo Description and IELTS Speaking Part 1 questions).

Coherence Patterns

Using logical connectors to guide the examiner/AI through your arguments.

Outstanding Vocabulary

Using “less common lexical items” naturally and accurately.

Range Demonstration

Proving you can use complex grammar (Conditionals, Passives, Relative Clauses).

Examiner/AI Psychology

Understanding exactly what triggers a high score and what raises a “red flag.”

The Brutal Truth

Most online teachers (even for DET) have never assessed a real standardized test. They don’t know the difference between a Band 6.5 and a Band 7, or a DET 105 and 120. I have. For 12 years. Assessing 6,000+ real tests. I bring that professional rigor to every single DET class.

The Ex-Examiner Difference

✅ Professional Assessment Background (12 Years)
✅ Training based on Official Marking Criteria
✅ Identifies “Invisible” Errors that Apps Miss
✅ Expert in both IELTS and DET Standards

❌ Guesswork about scoring criteria
❌ Generic “Conversation Practice”
❌ No strategy for beating the algorithm
❌ Lack of rigorous feedback

Book Your Free Strategy Session: In 30 minutes, I will evaluate your English using my professional examiner standards and tell you exactly what you need to do to reach your target DET or IELTS score.

Book Free Strategy Session →

Email: [email protected] | WhatsApp: +44 (0)28 4389 1123