Frequently Asked Questions

The Missing Workbook is a structured English vocabulary dictionary and study app for serious learners. Look up a word and you get CEFR level, US/UK IPA pronunciation, parts of speech, senses, examples, synonyms, antonyms, and etymology. Then you can add the word to spaced-repetition study instead of copying it into a separate flashcard app.

The product thesis is simple: English vocabulary is easier to learn when you can see pronunciation, meaning, usage, roots, affixes, phrases, idioms, and review history in one connected system.

It is for intermediate-to-advanced English learners, writers, test takers, teachers, and language nerds who want more than a quick definition.

The app is dense on purpose. A word page can show IPA, CEFR, senses, example sentences, synonyms, antonyms, related words, etymology, roots, affixes, phrase links, idiom links, and study state. The goal is not to hide complexity; it is to make the complexity navigable.

A normal dictionary answers "what does this word mean?" The Missing Workbook also asks:

• How hard is this word?
• How is it pronounced in US and UK English?
• Which sense is being used?
• Which roots and affixes built it?
• Which phrases and idioms does it appear in?
• Have I studied it before?
• When should I review it again?

Use a normal dictionary when you need a quick answer. Use The Missing Workbook when you want the word to become part of your usable vocabulary.

Anki and Quizlet are general flashcard systems. You bring or build the deck.

The Missing Workbook is a dictionary plus a built-in study system. The cards come from real word entries that already have pronunciation, senses, examples, etymology, and related vocabulary. You can look up a word, understand it, add it to your deck, and review it later without leaving the product.

Use the search bar at the top of the app. Search by:

• The word itself, such as ephemeral, run, or sanguine
• Meaning or definition keywords
• Roots or affixes, such as luc, bene, circum, or -tion
• Phrases and idioms
• Pronunciation or IPA fragments where available

Exact word matches come first, followed by related and partial matches.

You can browse:

• Words
• Phrases
• Idioms
• Grammar and usage patterns
• Roots
• Affixes
• Topics
• Minimal pairs
• Public-domain reading material
• The Etymology Atlas
• The IPA manual
• The usage reference

CEFR is the Common European Framework of Reference for Languages. We use it as a rough difficulty ladder from A1 through C2, plus C2+ for rare or highly specialized reference words.

It is a useful organizing scale, not a perfect measurement. A word can be easy for one learner and hard for another depending on language background, reading habits, and domain knowledge.

The Etymology Atlas is a graph of how words connect to roots, affixes, and related word families. Instead of showing etymology as a paragraph only, it lets you move through the structure of a word.

Try examples like:

• ephemeral
• benevolent
• circumspect
• incandescent

No. Etymology can be uncertain, especially across old languages, borrowed forms, folk etymology, and words with disputed histories. We aim for useful, transparent learning explanations, but you should treat etymology notes as learning aids rather than final authority.

If an etymology looks wrong, please send the word URL and a source.

Add a word, phrase, minimal pair, or usage topic to your deck. The scheduler chooses when it should appear again. After each review, you rate your recall from 1 to 4:

• 1 - Again: you missed it or could not recall it.
• 2 - Hard: you got it, but it was slow or uncertain.
• 3 - Good: you knew it.
• 4 - Easy: it was effortless.

The app uses those ratings to schedule future reviews.

FSRS-5 is a modern spaced-repetition scheduler. It models how stable and difficult a memory is, then schedules the next review around a target recall probability.

The Missing Workbook uses a hybrid scheduler: early reviews use a stable SM-2 warmup, then gradually blend into FSRS as the app has enough data about your memory.

Browsing the dictionary and reference material is free. A free account can save progress and study A1 vocabulary. Pro unlocks study access beyond A1 and the full atlas/study surfaces across the rest of the vocabulary.

Yes. Word, phrase, minimal-pair, and usage-study systems track progress separately because knowing a word does not automatically mean you can recognize its idioms, collocations, pronunciation contrasts, or usage patterns.

Yes. The app estimates forgetting based on reviews inside the app. If you are also reading, writing, tutoring, or using other tools, the estimates may be too pessimistic or imperfect. That is expected.

Audio uses your browser's built-in speech synthesis. Nothing needs to be streamed from a separate audio server for ordinary playback. Voice quality depends on your browser and operating system.

The IPA manual explains every IPA symbol, stress mark, and diacritic used in the app's pronunciation transcriptions. You can click example words to hear them.

Writing analysis lets you paste or upload plain text and get a structured report about vocabulary level, grammar/usage issues, organization, register, and revision opportunities. It is a learning aid, not a professional editing, legal, academic-integrity, or admissions service.

The companion grades a passage against a CEFR threshold and highlights harder words. The HTML page is Pro-gated; the JSON analysis endpoint may be available for scripts and agents with rate limits and size caps.

Current public pricing is:

• $15/month - billed monthly
• $120/year - billed annually

Payments are handled by Stripe.

Open /billing while signed in and use the Stripe-hosted billing portal. Cancellation stops future renewal charges. Access continues until the end of the billing period already paid.

If billing does not open, email missingworkbook@h15n.com.

The free tier is the trial. Try the dictionary and A1 study before upgrading.

Unless required by law or caused by a billing error, monthly, annual, and payments are not refundable. If something genuinely unusual happens, such as a duplicate charge, account-access problem, medical emergency, or financial hardship, email us and we will review it case by case.

If you want to move from monthly to annual, email us. We can usually handle plan changes through Stripe, subject to Stripe's capabilities and the details of your current plan.

No for browsing. Yes for saved study progress, deck state, review history, billing, and account-specific settings.

Yes, if Google Sign-In is available. We use it only for authentication. We do not post on your behalf or access your Google Drive, contacts, calendar, or email.

Use "Forgot password?" on the sign-in page. The reset link is sent by email and expires.

There is not yet a self-serve export UI. If you need a CSV or readable export of your review history or card state, email missingworkbook@h15n.com.

Email missingworkbook@h15n.com. We aim to delete or anonymize personal account and study data within 30 days unless we need to keep limited records for legal, billing, security, fraud-prevention, or accounting reasons.

No. We do not sell personal information or use it for cross-site behavioral advertising.

The app contains a curated English vocabulary across A1 through C2+, with headwords, aliases, IPA, senses, examples, synonyms, antonyms, etymology, roots, affixes, and related words where available. Coverage grows over time.

The app includes thousands of phrases, collocations, and idioms selected for usefulness and study value. Phrase and idiom coverage is still expanding, so missing items are expected.

The dictionary is curated, not a complete record of every English word. Some rare, domain-specific, archaic, slang, proper-noun, or newly emerging words may be missing or assigned a rough CEFR level. Send corrections when you find them.

The data is a mix of public-domain material, open datasets, generated seed data, manual curation, and product-specific organization. The most important layer is the app's editorial structure: CEFR grouping, search, etymology connections, study state, and cross-links between words, phrases, idioms, roots, affixes, usage, and pronunciation.

Use the feedback button in the app or email missingworkbook@h15n.com. Include the URL, what you expected, what happened, and any source you trust.

Email missingworkbook@h15n.com. One inbox handles support, privacy, billing, corrections, legal notices, and partnership inquiries.