Check Sentence Skill

Purpose

Validate a sentence or phrase for grammatical correctness, semantic accuracy, and modern English usage. Fix errors with minimal intervention — preserve the user's original wording as much as possible. Then offer a few alternative phrasings that express the same idea more naturally, concisely, or effectively — written as a human would write them, not as AI generates them.

Behavior

Step 1 — Read the input

Accept a sentence, phrase, or short passage from the user (can be casual, formal, written, or spoken-style text).

Step 2 — Check for

• Grammar errors: subject-verb agreement, tense, articles (a/an/the), prepositions, pluralization, punctuation
• Semantic errors: words that are used incorrectly or don't mean what the user intends
• Naturalness: is this how a native speaker would say it in modern English? (Flag if something is technically correct but sounds odd or outdated)
• Register mismatch: is the formality level consistent? (e.g. mixing slang with formal phrasing)

Step 3 — Output format

If the sentence is correct:

✅ Correct. Nothing to fix.

Optionally add one line if there's a minor nuance worth noting (e.g. subtle register note). Keep it brief.

If the sentence has errors:

❌ [Corrected sentence]

What changed: [Short, plain-English list of fixes — one line each, no jargon]

Always follow with alternatives (whether or not there were errors):

Alternatives:

• [Option 1]
• [Option 2]
• [Option 3 — optional, only if genuinely different]

Each alternative must express the same core meaning. Label register/quality briefly if the difference isn't obvious. Aim for 2–3 alternatives; skip only if the original is already so idiomatic that no useful alternative exists.

Step 4 — Full corrected passage (always include, multi-sentence input only)

If the input is a passage (more than one sentence/paragraph — not a single short sentence or phrase), end the response with the complete corrected version, as one clean block, with no per-sentence breakdown mixed in, no ✅/❌ markers, no "what changed" notes, and no commentary before or after it. This is the copy-paste-ready version: only the corrections from Step 3 applied, nothing else rewritten or improved beyond that.

Format it like this, as the last thing in the response:

Full corrected version:

[entire passage, corrected, ready to copy-paste]

For a single sentence/phrase input, skip this step — the corrected sentence in Step 3 already serves that purpose.

Rules for Alternatives — Anti-Slop

Alternatives must sound like a human wrote them. Before writing each one, run it through the checks below. If it fails any, rewrite it.

Read references/slop-phrases.md and references/slop-structures.md for full lists. The key rules:

What to cut

• No throat-clearing openers: "Here's the thing", "The truth is", "It turns out", "At its core"
• No adverbs: Kill all -ly words. No "really", "genuinely", "deeply", "fundamentally", "truly"
• No em dashes: Use commas or periods instead
• No vague declaratives: If a sentence says something is important without naming the specific thing, rewrite it
• No filler phrases: "At the end of the day", "When it comes to", "In today's world", "It's worth noting"

What to avoid structurally

• No binary contrasts: Don't write "Not X. It's Y." — state Y directly
• No dramatic fragmentation: No staccato one-liners stacked for fake profundity
• No rhetorical setups: "What if...?", "Think about it:", "Here's what I mean:"
• No negative listings: Don't list what it isn't before saying what it is
• No passive voice: Every sentence needs a human subject doing something
• No narrator-from-a-distance: "People tend to..." → use "you"
• No false agency: Inanimate things don't perform human actions ("the culture shifts", "the data tells us")
• No three-item lists by default: Two items usually beat three
• No uniform rhythm: Vary sentence length. Don't end every alternative the same way

What to do instead

• Lead with a subject doing something
• Be specific — name the exact thing
• Vary sentence structure across the alternatives (don't make them all parallel constructions)
• Put the reader in the scene where possible ("you" beats "people")
• Trust the reader — no hand-holding, no softening, no justification

Quick self-check before writing each alternative

• Any adverbs? Kill them.
• Any passive voice? Find the actor, make them the subject.
• Any em dashes? Remove. Use commas or a period.
• Three consecutive sentences same length? Break one.
• Sounds like a LinkedIn pull-quote? Rewrite it.
• Starts with a Wh- word (What/When/Where/Why/How)? Restructure — lead with the subject.
• Any "not X, it's Y" contrast? State Y directly, drop the negation.

Rules for Corrections

• Never change wording unless it is wrong. If a word is correct but informal, note it — don't replace it.
• Never rewrite the sentence into something the user didn't intend. The correction must preserve intent; the alternatives may reframe.
• Minimal output — no long explanations. The user wants a fast check, not a grammar lesson. One short line per fix max.
• If there's ambiguity about intent (a phrase could mean two things), flag it briefly before giving alternatives.
• For non-native English speakers: be forgiving about minor stylistic things that are technically fine.

Examples

Input: "He don't know nothing about it."

❌ He doesn't know anything about it.

What changed: don't → doesn't (subject-verb agreement); double negative corrected.

Alternatives:

• He has no idea about it. (conversational)
• He's in the dark on this. (idiomatic)

Input: "I am working since 3 hours."

❌ I have been working for 3 hours.

What changed: Tense: ongoing action requires present perfect continuous; since → for (use for with a duration, since with a point in time).

Alternatives:

• Three hours in and still going. (punchy, informal)
• I've been at this for three hours. (casual, natural)

Input: "The informations are incorrect."

❌ The information is incorrect.

What changed: information is uncountable — no plural; verb adjusted to match.

Alternatives:

• This information is wrong. (shorter, direct)
• These details are off. (if referring to multiple specific items)

Input (multi-sentence passage): "He don't know nothing about it. He is working since 3 hours on it."

❌ He doesn't know anything about it.

What changed: don't → doesn't (subject-verb agreement); double negative corrected.

❌ He has been working on it for 3 hours.

What changed: Tense: ongoing action requires present perfect continuous; since → for.

Alternatives:

• He's clueless about it, three hours in and counting. (combines both, informal)

Full corrected version:

He doesn't know anything about it. He has been working on it for 3 hours.