Grammarcoach

What Grammarcoach is for

"Explain comma splices", "what's the difference between lay and lie", "give me 5 practice questions on who vs whom", "what are common grammar mistakes with pronouns" — a fully local, general/adult-audience English grammar reference and practice generator.

Not a duplicate of Brightwise

Brightwise's grammar_practice tool is a kids' tool (grades 1-8) covering parts of speech, basic punctuation, and sentence structure. Grammarcoach is a completely separate bank targeting adult/teen problem areas: subject-verb agreement edge cases, comma splices, dangling modifiers, who vs. whom, and eight classic confusable-word pairs — lay/lie, affect/effect, its/it's, your/you're, there/their/they're, then/than, fewer/less, and whose/who's. No practice item or explanation is shared between the two connectors.

What it does

list_topics lists the four rule topics, the eight confusable word pairs, and every practice-item topic. explain_rule gives the full explanation and correct/incorrect examples for one rule topic. confusable_word_pair gives the explanation, a memory trick, and real example sentences for one word pair. practice_item generates one or more multiple-choice practice items — each with a genuinely verified-correct answer and an explanation. common_errors returns a wrong-vs-right reference organized by category (agreement, punctuation, modifiers, pronoun_case, word_choice).

How every practice item's correctness is guaranteed

There are two, and only two, sources for a practice item, and both are verified before request time:

1. Subject-verb agreement items are generated fresh at request time from a hand-checked verb-conjugation table (11 verbs, each with its base and third-person-singular form written and checked by hand) crossed with a set of subjects marked singular or plural. The correct answer is a direct lookup from that table — there's no inference step that could get it wrong.
2. Every other topic — comma splices, dangling modifiers, who/whom, and all eight confusable pairs — draws from a bank of hand-written multiple-choice items whose correct answer was checked by hand against the rule being tested, before this connector ever shipped. Request-time randomness only chooses which item to serve and shuffles the display order of its options; it never touches which option is marked correct.

What is hand-authored vs. computed

Every rule explanation, confusable-pair explanation, and practice-item template is hand-authored and checked against standard general grammar references. Item selection and multiple-choice option shuffling are computed at request time; the subject-verb-agreement generator additionally computes its correct answer live from the checked conjugation table.

What it is not

This is a reference and practice tool for common English usage problems, not a comprehensive style guide, not a substitute for a copyeditor, and not coverage of every grammar rule in English — it focuses specifically on the handful of problem areas and confusable pairs that trip up adult writers most often.

Built and maintained by Unify Dynamics LLC. Contact: agent@connectorbay.com.

Grammarcoach — Privacy Policy

Effective 28 September 2026. Unify Dynamics LLC ("we", "us"), Menlo Park, California.

What Grammarcoach is. Grammarcoach is a connector (an MCP server and REST API) that AI assistants and personal agents call on your behalf for a fully local English grammar reference and practice generator. You interact with your assistant; the assistant sends us only the values needed for that one response.

What we receive. The arguments of each tool call — a rule topic, a confusable-word-pair name, a practice topic and count, or a common-errors category — the technical headers needed to serve the request (an IP address or a client identifier supplied by the assistant, and a Pro API key if you have one), and standard server logs.

Everything is answered or generated locally and nothing is stored. Rule explanations, confusable-pair content, and practice-item templates are read from a bundled, hand-authored reference file; subject-verb agreement practice items are generated from a small bundled conjugation table. No request is forwarded to any third party, and no query is logged in request bodies, recorded, or used to train anything.

What we do not receive or store. We do not receive your conversation with the assistant, your name, or any other identifying information, and we do not build a learning profile from your queries — each call is answered independently.

Rate-limit counters (a client identifier and timestamps) are held in memory for at most 24 hours. Hosting-provider access logs, which contain IP addresses and request paths but not request bodies, are retained for up to 30 days for security and abuse prevention.

Sub-processors. None — every tool is answered or generated locally. Hosting: Vercel (United States regions).

Legal bases and your rights. For users in California, the EU/UK and elsewhere, our processing is necessary to provide the service you request through your assistant. Because we store no personal data beyond short-lived logs, requests to access, correct or delete personal data are usually satisfied automatically; you can still contact agent@connectorbay.com and we will respond within 30 days. We do not sell or share personal information and do not use your data to train models.

Children. Grammarcoach is a general/adult-audience grammar-reference tool operated through the adult or organization running the AI assistant.

Changes. We will post changes here with a new effective date.

Grammarcoach — Terms of Service

Effective 28 September 2026. These terms govern use of the Grammarcoach connector ("the Service") operated by Unify Dynamics LLC ("we", "us").

1. The Service. Grammarcoach returns English grammar-rule explanations, confusable-word-pair reference, generated multiple-choice practice items, and a common-errors reference, from a hand-authored reference and a small checked conjugation table bundled with the server. It is accessed through an AI assistant or directly over MCP or HTTP.
2. General reference, not a comprehensive style guide. Grammarcoach covers a focused set of common problem areas and confusable-word pairs for general/adult use, not the full breadth of English grammar, and it is not a substitute for a copyeditor, writing tutor, or style-guide subscription.
3. Randomly selected practice content. Which practice item is generated for a given request, and the display order of its multiple-choice options, is selected at request time and is not guaranteed to be unique or non-repeating across calls. Every marked-correct answer, however, was verified by hand (or generated from a checked lookup table) before being served — see the service's documentation for how.
4. Acceptable use. Automated use within the published rate limits is welcome.
5. Availability. The Service is provided "as is" without warranty. We may change, limit or discontinue it at any time.
6. Data. Our Privacy Policy describes what we process. In short: your request is answered on our server and nothing is stored.
7. Pro keys. Optional Pro API keys are issued at our discretion, are personal to the holder and may be revoked for abuse.
8. Liability. To the fullest extent permitted by law, Unify Dynamics LLC is not liable for any loss arising from use of or reliance on the Service. Our total liability is limited to US $100.
9. Governing law. California law; venue in San Mateo County, California.
10. Contact. Unify Dynamics LLC · agent@connectorbay.com · https://connectorbay.com/grammarcoach

Grammarcoach support

Email agent@connectorbay.com. We answer within two business days.

• MCP endpoint: https://grammarcoach.connectorbay.com/mcp
• REST API: https://grammarcoach.connectorbay.com/openapi.json
• Live status: https://grammarcoach.connectorbay.com/health

When you report a problem, include the question you asked your agent, roughly when, and which agent you used (for example Claude, ChatGPT or Gemini). Never send us passwords, account numbers or ID numbers. Grammarcoach never asks for them.