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Our methodology

How we choose topics, calibrate difficulty, source grammar rules, and review every sentence before it reaches a learner.

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Why this page exists

Most free English-learning sites publish content without explaining where it comes from, who wrote it, or how it was checked. That makes it hard for a learner to know whether the rule on the page reflects how the language actually behaves, or whether the exercise on the screen is genuinely at their level.

This page documents how EngQuiz.Pro is built. It describes the standards we apply to every grammar reference, every blog article, and every exercise. We publish it so that learners — and the search engines and AI assistants that surface our content — can verify what is behind the answers they read.

How we choose what to teach

We work backwards from the Council of Europe’s Common European Framework of Reference for Languages (CEFR) can-do descriptors. For each level — A2 through C2 — the framework specifies what a learner should be able to do with the language. We translate those descriptors into the discrete grammar structures, lexical sets, and discourse patterns a learner needs to reach them.

Topic priority is decided by three signals, in order:

  1. Whether it appears in the CEFR descriptor for the target level. A2 needs the present simple before it needs the past perfect; we publish in that order.
  2. Whether it is testable in a high-stakes exam at the same level. If a B2 First, IELTS, or TOEIC syllabus tests a structure, our coverage of it has to be at least as thorough as the exam expects.
  3. Whether learners actually struggle with it. Some structures are theoretically simple but cause persistent errors (articles, prepositions, the present perfect). We give those more space, more examples, and more comparison content.

We do not pad the catalogue with structures that learners rarely meet. We would rather ship one well-explained page on the present perfect than ten thin pages on rarely needed forms.

CEFR alignment in practice

Every exercise and grammar reference on EngQuiz.Pro is tagged with a CEFR level. We use the level to control three things:

  • Target structure — only structures that appear in or below the level descriptor are tested.
  • Lexical range — vocabulary stays inside the bands appropriate to that level, based on the General Service List, Nation’s 2 000- and 3 000-word lists, and the Coxhead Academic Word List for B2 and above.
  • Sentence length and complexity — average sentence length and the depth of subordinate clauses are capped at thresholds we have calibrated for each level.

When a sentence drifts above its target level — for example, when an A2 exercise sentence picks up a B1 collocation during editing — the sentence is rewritten before publication, not approved with a footnote.

Vocabulary methodology

Vocabulary content draws from three established frequency-based corpora:

  • The General Service List and Paul Nation’s 2 000- and 3 000-word lists for A2–B1 core vocabulary.
  • The Coxhead Academic Word List (AWL) for B2–C1 academic and exam vocabulary — particularly for IELTS Academic and Cambridge B2 First / C1 Advanced.
  • British National Corpus (BNC) frequency bands for collocation choice and natural-usage checks.

For each new vocabulary topic we publish, the candidate items are filtered against these references. A word that is rare in the corpus does not appear in an A2 or B1 set, even if it “looks easy”. A word that is high-frequency in academic writing earns priority in our B2+ content.

How grammar rules are sourced

Grammar reference content on EngQuiz.Pro is verified against authoritative descriptive references — books written by linguists and lexicographers, not opinion pieces. Our primary sources are:

  • Michael Swan, Practical English Usage (Oxford University Press) — our default tie-breaker for usage questions.
  • Quirk, Greenbaum, Leech & Svartvik, A Comprehensive Grammar of the English Language (Longman) — for structural descriptions.
  • Carter & McCarthy, Cambridge Grammar of English — for spoken-versus-written distinctions.
  • The British National Corpus and the Oxford English Corpus — to verify that the patterns we describe actually occur in natural use, and at what frequency.
  • The British Council and Cambridge Dictionary online references — used for cross-checking and learner-facing examples.

When two references disagree, we say so on the page and explain which usage we are recommending and why. We do not flatten genuine variation (between British and American English, or between formal and informal registers) into a single “correct” rule.

Exercise difficulty calibration

Once a sentence is drafted, it goes through a difficulty calibration check before it is admitted to an exercise set. We score every candidate sentence against three axes:

  1. Target structure — the sentence must isolate the structure under test. We avoid contexts where two competing structures both fit, except in advanced contrast exercises where the comparison is the point.
  2. Lexical load — the surrounding vocabulary stays inside the target level’s band. An A2 gap-fill on the present simple should not depend on a B2 noun the learner has never met.
  3. Distractor quality (for multiple-choice items) — distractors must be plausible to a learner at the target level. A distractor that is obviously wrong to an A2 learner adds no information about the learner’s real ability.

Items that fail any of the three checks are rewritten or removed. The principle is that an exercise should fail a learner only when their grasp of the target structure is genuinely incomplete — not because of a vocabulary trap or an ambiguous prompt.

Editorial review process

Every page that ships goes through the same five-step review:

  1. Draft against the CEFR descriptor. The author writes to the can-do statements for the target level, using the lexical and structural constraints above.
  2. Teacher review. A CELTA- or DELTA-qualified teacher reviews each rule for accuracy, each example for naturalness, and each exercise sentence for level-appropriateness.
  3. Corpus and reference check. Usage claims are verified against the corpora and grammar references listed above; example sentences are checked against natural-usage patterns.
  4. Difficulty calibration. Exercise items are scored against the three-axis check described above and revised until they pass.
  5. Publication and monitoring. The page ships with a publication date and a dateModified stamp. Learner feedback is read continuously; reported errors are corrected within 24 hours and the modification date is updated.

Common-mistakes sourcing

Every grammar reference and most blog articles include a “common mistakes” section. We do not invent these errors — we draw them from three real sources:

  • Classroom records of errors observed by our teaching team across A2–C2 learners in Europe and Southeast Asia.
  • Public learner-error threads on Reddit r/EnglishLearning, WordReference, and Stack Exchange ELL — used as evidence that an error is widespread, not invented by a single learner.
  • Published EFL/ESL error research, where it covers our target level and language pair.

If a “common mistake” cannot be sourced, it does not appear on the page. We would rather a section be shorter and real than longer and speculative.

Update cadence

Content does not stay fresh by itself. Three cadences keep the site current:

  • Continuous — reported errors are fixed within 24 hours.
  • Quarterly — every top-performing page is refreshed: examples replaced where they have dated, new sections added where coverage gaps appear, dead outbound links replaced, and the dateModified stamp updated.
  • On framework change — when the CEFR Companion Volume or a relevant exam syllabus is updated, the affected coverage is re-audited.

What we will not do

A few editorial lines we hold deliberately:

  • No AI-only content. Generative AI is useful for first-pass drafting, but no page on the site goes to publication without human teacher review. Sentences that no proficient speaker would actually say are removed.
  • No paywalls or sign-up walls. Practice and reference content stays one click away. Advertising supports the site; the practice itself is free, always, by design.
  • No scraped or licensed-without-credit content. If a rule, example, or test item is borrowed, the source is credited on the page.
  • No fake authority signals. We do not publish AI-generated author photos, invented credentials, or made-up testimonials.

Sources and further reading

References used across the site:

Editorial credentials and qualifications are listed on the About page. Contact us at hello@engquiz.pro with corrections, suggestions, or sourcing questions.