Read runtime and advisory rules before applying this skill. Other Foreman layers and the catalog are in ../../content/, relative to this SKILL.md.
Grammar and Mechanics
A misplaced apostrophe has never killed a company. But it has killed pitch decks, alienated investors, and quietly disqualified founders from rooms they never knew they were being evaluated for. Grammar errors in business writing operate as a credibility tax: each one individually minor, collectively devastating. Readers may not consciously register the error, but they register its effect -- a subtle downgrade in how seriously they take the author. The founder who writes "it's revenue model" instead of "its revenue model" in a Series A memo has communicated something unintended: carelessness with details. And carelessness with details is precisely the trait investors screen for.
The rules that follow are not pedantic niceties. They are the twelve grammatical principles and twelve punctuation conventions that, when violated, most reliably damage professional credibility.
The Framework
Twelve Essential Grammar Rules
1. Starting sentences with And or But is perfectly acceptable. The myth persists from secondary school, but the best prose writers have always done it. Monosyllabic conjunctions create tighter transitions than however or additionally.
2. Ending a sentence with a preposition is fine. The prohibition traces to Latin syntax and has no basis in English grammar. "What will the new product be used for?" reads more naturally than the contorted alternative.
3. Use well as an adverb, not good. "The team performed well" -- not "performed good." The exception: set phrases like "a good many" or "did it but good."
4. The subject determines the verb's number. Prepositional phrases that follow the subject create "false attraction" -- the verb should match the subject, not the nearest noun.
- Wrong: "The details of the customized work is delaying the project."
- Right: "The details of the customized work are delaying the project."
5. Either and neither as subjects take singular verbs. "Neither of our expansion options provides a total solution" -- not provide.
6. With neither/nor and either/or, the second element controls the verb. "Neither the regional managers nor the vice-president likes the proposed theme."
7. Flat adverbs (thus, doubtless) take no -ly ending. Adding -ly to words that are already adverbs produces nonstandard forms: thusly and doubtlessly are both incorrect.
8. Conjunctive adverbs (however, therefore) cannot join independent clauses with just a comma. This produces the comma splice. Use a semicolon before and a comma after: "The campaign is ready; however, the CEO has yet to approve it."
9. That introduces restrictive clauses (no comma); which introduces non-restrictive clauses (with a comma). "The report that you requested is ready" vs. "The report, which you requested, is ready."
10. Pronouns must agree with their antecedents in number. "A shareholder may cast his or her vote" -- or restructure the sentence to use the plural: "Shareholders may cast their votes."
11. Avoid double negatives. Subtle forms include couldn't scarcely (use could scarcely) and not...but constructions that create ambiguity.
12. Use standard English consistently. Watch for nonstandard forms that creep in from speech: shouldn't of (should be shouldn't have), drug as past tense of drag (should be dragged).
Twelve Punctuation Essentials
| # | Rule | Example |
|---|---|---|
| 1 | Use the serial (Oxford) comma before the final item in a list | "Revenue, costs, and margins" |
| 2 | Place commas and periods inside quotation marks | She said "the deal is closed." |
| 3 | Use a semicolon to join related independent clauses | "Sales rose 14%; margins held steady." |
| 4 | Use a colon to introduce a list, explanation, or elaboration | "Three priorities: hiring, retention, and culture." |
| 5 | Hyphenate compound adjectives before a noun | "A well-written proposal" (but "the proposal was well written") |
| 6 | Use an em dash for emphasis or interruption | "The acquisition -- if approved -- will close in Q3." |
| 7 | Apostrophes show possession, not plurality | "The company's revenue" not "the company's revenue's" |
| 8 | Its (possessive) vs. it's (contraction of "it is") | "The firm increased its revenue" |
| 9 | Use parentheses for supplementary information | "Revenue ($4.2M) exceeded projections." |
| 10 | End declarative sentences with a single period | Never use double periods or exclamation marks in formal prose |
| 11 | Use a comma after introductory phrases | "After reviewing the data, the team recommended expansion." |
| 12 | Do not use a comma to separate a subject from its verb | Wrong: "The CEO, approved the budget." |
Common Usage Confusions
| Confused Pair | Distinction |
|---|---|
| affect / effect | Affect is usually a verb (to influence); effect is usually a noun (a result). "The policy will affect margins. The effect will be significant." |
| that / which | That restricts; which adds information. Use which with commas. |
| who / whom | Who is the subject; whom is the object. Test: substitute he/him. "Who called?" (he called). "To whom was it sent?" (sent to him). |
| fewer / less | Fewer for countable nouns; less for uncountable. "Fewer employees, less revenue." |
| comprise / compose | The whole comprises its parts. The parts compose the whole. "The board comprises seven members." |
| ensure / insure | Ensure means to make certain; insure relates to insurance policies. |
| principal / principle | Principal is a leader or primary; principle is a fundamental rule. |
Prompts
Prompt 1 -- Grammar Audit:
Review the following business document for grammar errors, focusing on subject-verb agreement, pronoun case, dangling modifiers, and parallel construction. For each error found, quote the original sentence, explain the specific rule violated, and provide a corrected version. Document: [paste text]
Prompt 2 -- Usage Confusion Scan:
Examine this text for commonly confused words (affect/effect, that/which, who/whom, fewer/less, comprise/compose, ensure/insure, principal/principle). Flag every instance, explain whether it is used correctly, and suggest corrections where needed. Text: [paste text]
Prompt 3 -- Punctuation Overhaul:
Audit this document for punctuation errors, paying special attention to comma splices, missing serial commas, incorrect apostrophe usage, and hyphenation of compound adjectives. Provide a corrected version with annotations explaining each change. Document: [paste text]
Prompt 4 -- Before/After Credibility Rewrite:
Here is a paragraph from an investor update I am preparing: [paste text]. Rewrite it to eliminate all grammar and punctuation errors while preserving the original meaning and tone. Then list every change made and the rule that motivated it.
Use Cases
Validation-Stage Founder Preparing a Pitch Deck A solo founder preparing a twelve-slide seed pitch discovers, after a grammar audit, that three slides contain subject-verb disagreements and one uses "it's" as a possessive. The investor reading the deck is a former English major who served as managing editor of the Stanford Law Review. These errors would have been the first -- and possibly the last -- things noticed. The grammar check costs fifteen minutes. The unchecked alternative could have cost the meeting.
Growth-Stage Company Publishing an Annual Report A 200-person company preparing its first public annual report submits the draft for a grammar and mechanics review. The audit catches 23 punctuation inconsistencies (mixed usage of serial commas), 7 that/which confusions, and a dangling modifier in the CEO's letter that accidentally attributes declining margins to the board of directors rather than to market conditions. The corrected version avoids an embarrassment that, once printed and distributed, could not be recalled.
Early-Traction Startup Drafting Client Contracts A B2B SaaS startup discovers its standard client proposal template contains "less" where "fewer" is required, inconsistent hyphenation of compound modifiers, and three instances of comma splices. Since this template has been sent to forty prospects over six months, the cumulative credibility impact is sobering. Correcting the template takes twenty minutes and elevates the professionalism of every future client interaction.
Anti-Patterns
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Hypercorrection. Overcorrecting grammar to the point of producing stilted, unnatural prose. Writing "to whom should I direct this inquiry?" in a Slack message to a colleague is technically correct and socially absurd. The goal is correctness appropriate to context, not grammatical maximalism.
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Grammar Policing in Feedback. Using grammar knowledge to publicly correct colleagues' writing rather than privately and constructively improving shared documents. Grammar competence used as a status signal breeds resentment, not better writing.
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Ignoring Grammar in Internal Documents. Treating grammar as relevant only for external communications. Internal memos, Slack messages, and team updates also shape how people perceive competence. Sloppy internal writing creates sloppy habits that leak into external documents at the worst moments.
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Relying Solely on Spell-Checkers. Spell-check tools catch "teh" but miss "their" when you meant "there." Grammar-checking software has improved but still mishandles subject-verb agreement in complex sentences, that/which distinctions, and subtle comma splices. Automated tools supplement human review; they do not replace it.
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Perfectionism as Procrastination. Endless grammar revision as a means of avoiding the more difficult work of actually saying something. A grammatically perfect document that says nothing of substance is a polished void.
By Stage
| Stage | Focus | Key Difference |
|---|---|---|
| Idea | Personal credibility in initial pitches | At the idea stage, the founder is the product. Grammar errors in early pitch materials disproportionately damage credibility because there is no product traction to compensate. |
| Validation | Pitch decks and investor communications | Documents begin circulating to external audiences -- investors, advisors, potential partners. Every document is evaluated as evidence of operational competence. |
| Early Traction | Client-facing proposals and contracts | Proposals, contracts, and onboarding materials now represent the company to paying customers. Grammar errors signal carelessness in a context where trust is still fragile. |
| Growth | Standardising templates and style guides | With multiple people writing on behalf of the company, inconsistency becomes the primary risk. A company-wide style guide and grammar checklist become organisational infrastructure. |
| Scale | Brand consistency across all communications | At scale, grammar and mechanics become part of brand management. Training programmes, editorial review processes, and style enforcement tools ensure consistency across hundreds of authors. |
Output Template
markdown# Grammar and Mechanics Audit: [Document Name] ## Summary - **Total errors found:** [number] - **Critical errors (meaning-altering):** [number] - **Credibility errors (noticeable but not meaning-altering):** [number] - **Style inconsistencies:** [number] ## Error Log | # | Original Text | Error Type | Rule Violated | Corrected Text | |---|--------------|------------|---------------|----------------| | 1 | [quote] | [grammar/punctuation/usage] | [specific rule] | [corrected version] | | 2 | [quote] | [grammar/punctuation/usage] | [specific rule] | [corrected version] | ## Recurring Patterns - [Pattern 1: e.g., "Consistent misuse of that/which throughout"] - [Pattern 2: e.g., "Serial comma used inconsistently"] ## Recommendations 1. [Specific recommendation for preventing recurrence] 2. [Style guide addition suggested]
Related Skills
- Tone and Engagement -- Correct grammar is necessary but not sufficient; tone determines whether technically correct prose actually connects with readers.
- Writing Effective Emails -- Email is the most frequent venue for grammar errors because speed and informality lower the writer's guard.
- Writing Memos and Reports -- Formal documents demand the highest standard of grammatical precision because they persist in the organisational record.
- Writing Performance Reviews -- Performance evaluations carry legal implications, making grammatical precision not merely a matter of style but of institutional risk.
- Revising and Editing -- The editing pass is where grammar errors are caught systematically rather than relying on instinct during drafting.
- Plain Language and Flow -- Many grammar errors stem from overly complex sentence constructions; plain language reduces the surface area for mechanical mistakes.
