About The Grammar Index

Our Mission

The Grammar Index is a comprehensive online English grammar reference designed for anyone who needs accurate, plain-English explanations — whether you're a student preparing for an exam, a teacher building lesson plans, an ESL learner studying in your second language, or a writer who just wants to get the details right.

We believe a good grammar reference shouldn't cost the price of a textbook or require a monthly subscription. The Grammar Index puts over 300 grammar topics at your fingertips with clear definitions, worked examples, and colour-coded categories — across the web, Windows, iOS, and Android — for one small one-time payment.

What's Inside

The index covers the full breadth of English grammar, organised into seven categories you can browse or search:

• Parts of speech — nouns, verbs, adjectives, adverbs, pronouns, articles, conjunctions, and more.
• Verbal forms — gerunds, infinitives, participles, aspects, conditionals, and tenses.
• Sentence structure — main, subordinate (dependent), relative (adjective), adverbial, and noun clauses, plus noun phrases, preposition phrases, complements, subjects, objects, and modifiers.
• Syntax rules — agreement, tense consistency, parallel structure, and common error patterns.
• Mechanics — capitalisation, abbreviations, contractions, prefixes, suffixes, and morphemes.
• Punctuation — every mark from the period to the interrobang, with British and American conventions.
• Phonics — phonemes, graphemes, digraphs, trigraphs, split digraphs, the schwa, stress, and Received Pronunciation.

Each entry includes a clear definition followed by up to ten worked examples — including correct-and-incorrect pairs where relevant, and the occasional funny one to keep the rules memorable. So you don't just see the rule; you see how it actually plays out in real sentences.

Built-in Quiz

Every edition now includes a quick five-question multiple-choice quiz. Open the topics you want to revise, then tap the quiz button: the app builds a tailored quiz from the entries you've actually studied, with randomised questions, randomised answer options, and freshly chosen distractors on every retake. Score, feedback, and a "try again with new questions" button. It's deliberately short — long enough to test understanding, short enough to slot into the end of a lesson.

Key Stage 2 & 3 Edition (Ages 7-13)

Our newest edition is a child-friendly version of The Grammar Index built for use across the major school platforms — Google Classroom, Microsoft Teams for Education, and Apple Store for Education. The content is aligned with the UK National Curriculum English programme of study (DfE glossary, DFE-00184-2013), so it covers every grammar term schools are expected to teach at Key Stages 2 and 3 — main, subordinate (dependent), relative (adjective), adverbial, and noun clauses included. The vocabulary, the examples, and the tone are all written for ages 7-13 — schools and pets and football and dragons rather than boardrooms and skyscrapers. Every topic card opens to show a clear definition, three right examples with the key word underlined, one wrong example with a friendly explanation of the mistake, and a small grammar joke at the bottom. Alongside the cards there's a quick quiz and a new Spelling Test: a pupil sees a sentence with a word missing and a row of spellings — only one is correct — then types the right word, locking in both visual recognition and recall. It draws on 1,000 curriculum spelling words spanning high-frequency words, homophones, commonly misspelled words, the Year 3-6 statutory lists, and Science, Maths, Geography and History vocabulary, with age-appropriate (and often funny) sentences.

A tool for teachers — the Custom list. The Custom button lets you choose exactly which topics appear, and the app remembers them next time it opens. A teacher can set a focused list — this week's topics, a revision set, or the trickiest areas — so pupils return to that same curated list each lesson instead of the whole catalogue. The selection is saved per device (it doesn't sync across the class automatically), so it's set once on each pupil's machine. Used well, it turns the reference into a directed learning plan. It lives at keystage.grammarindex.com and is unlocked with a Gift / Sponsorship licence — see our pricing page for sponsor tiers covering a single classroom, an entire school, or every school in a district.

Built for Schools and Colleges

The Grammar Index is designed with educational institutions in mind. Our institutional licensing makes it affordable for schools, colleges, and universities to give every student a reliable English grammar reference on every device they own — laptops, tablets, and phones — for as little as 50 cents per seat at scale.

Administrators purchase a single licence key and distribute access to entire classes or year groups. Each key supports multiple devices, so students don't lose access when they switch between school computers and personal devices at home.

Designed for ESL and EFL Learners

For learners in countries where English isn't the first language, The Grammar Index provides a structured, easy-to-navigate reference written in plain English. Topics are explained without jargon and illustrated with practical examples, so concepts like the subjunctive mood, the perfect aspect, or the Oxford comma become approachable rather than intimidating. The same licence works for teachers preparing ESL lessons and students using the app for self-study.

Cross-Platform, Offline-Friendly

The Grammar Index runs as a web application in any modern browser, as a native desktop app for Windows, and as native mobile apps for iOS and Android. Your licence works across all platforms — buy once, use everywhere. The native apps work offline once installed, so students can study on the train, in class, or wherever they happen to be.

Why Pay Once, Not Subscribe

Most grammar tools today charge a monthly fee, which can add up fast — especially for institutions buying hundreds of seats. The Grammar Index is a one-time purchase because grammar itself doesn't change every month. You pay once, you keep access, and updates to the content (new entries, refined examples) are free for the lifetime of your licence.