eos-usage skill

---
name: eos-usage
description: Strunk & White grammar review using the 11 elementary rules from "Elements of Style" Chapter I. Use when checking mechanics, punctuation, and grammatical correctness.
user-invocable: true
---

# Elements of Style: 11 Rules of Usage

Review writing against Strunk & White's 11 elementary rules of usage from Chapter I.

## Instructions

Analyze the provided text for grammatical and mechanical errors. Flag specific violations with line numbers or quotes where possible.

### Output Format

**Text Under Review**: [title or brief description]

---

## Usage Review

| # | Rule | Status | Issues Found |
|---|------|--------|--------------|
| 1 | Form possessive singular with 's | Pass/Needs Work/N/A | [issues] |
| 2 | Use serial comma | Pass/Needs Work/N/A | [issues] |
| 3 | Enclose parenthetic expressions in commas | Pass/Needs Work/N/A | [issues] |
| 4 | Comma before conjunction + independent clause | Pass/Needs Work/N/A | [issues] |
| 5 | No comma splice | Pass/Needs Work/N/A | [issues] |
| 6 | No sentence fragments | Pass/Needs Work/N/A | [issues] |
| 7 | Use colon to introduce lists/appositives | Pass/Needs Work/N/A | [issues] |
| 8 | Use dash for abrupt breaks | Pass/Needs Work/N/A | [issues] |
| 9 | Subject-verb agreement | Pass/Needs Work/N/A | [issues] |
| 10 | Proper pronoun case | Pass/Needs Work/N/A | [issues] |
| 11 | Dangling modifiers | Pass/Needs Work/N/A | [issues] |

---

## Errors Found

### Rule 5: Comma Splices

| Location | Error | Correction |
|----------|-------|------------|
| [line/quote] | "It is cold, we should go inside" | "It is cold; we should go inside" OR "It is cold, so we should go inside" |

### Rule 6: Sentence Fragments

| Location | Fragment | Suggested Fix |
|----------|----------|---------------|
| [line/quote] | [fragment] | [complete sentence] |

### Rule 11: Dangling Modifiers

| Location | Error | Correction |
|----------|-------|------------|
| [line/quote] | "Walking down the street, the trees were beautiful" | "Walking down the street, I noticed the beautiful trees" |

---

## Rule Reference

1. **Form the possessive singular by adding 's** — Charles's friend, Burns's poems, the witch's malice. Exceptions: ancient proper names ending in -es or -is (Jesus', Moses'), and common idioms (for conscience' sake).

2. **In a series of three or more, use a comma after each term except the last** — red, white, and blue. The serial comma prevents ambiguity.

3. **Enclose parenthetic expressions between commas** — "The best way to see a country, unless you are pressed for time, is to travel on foot." If the interruption is slight, commas may be omitted.

4. **Place a comma before a conjunction introducing an independent clause** — "The early records are obscure, but they suggest..." This rule applies when both clauses are independent (could stand alone).

5. **Do not join independent clauses with a comma** — This error is the "comma splice." Wrong: "It is cold, we should go inside." Right: "It is cold; we should go inside" or "It is cold. We should go inside."

6. **Do not break sentences in two** — Avoid sentence fragments. "I met them on a Cunard liner many years ago. Coming home from Liverpool to New York." The second part should not stand alone.

7. **Use a colon after an independent clause to introduce a list, appositive, amplification, or illustrative quotation** — "The situation is perilous: our enemies are many, our supplies few."

8. **Use a dash to set off an abrupt break or to announce a long appositive or summary** — "His first thought on getting out of bed—if he had any thought at all—was to get back in again." Use sparingly; frequent dashes give writing a breathless quality.

9. **The subject and verb must agree in number** — "The bittersweet flavor of youth—its trials, its joys, its adventures, its challenges—are not soon forgotten" is wrong; use "is."

10. **Use the proper case of pronoun** — "between you and I" is wrong; use "between you and me." In compound constructions, test each pronoun alone.

11. **A participial phrase at the beginning of a sentence must refer to the grammatical subject** — "Walking down the street, the trees were beautiful" is wrong (trees weren't walking). Fix: "Walking down the street, I noticed the beautiful trees."

---

## Summary

**Grammar Accuracy**: [Clean/Minor Issues/Significant Errors]

**Most Common Error Type**: [error category]

**Corrections Needed**:
1. [Highest priority fix]
2. [Second priority]
3. [Third priority]

## Guidelines

- Not all comma usage is covered by these rules—focus on the specific patterns described
- Rule 2 (serial comma) is a style choice in some guides; Strunk & White advocate for it
- Some fragments are intentional for effect in creative writing
- Technical writing may have different conventions for colons and lists

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