Core Sentence Rules: Build Stronger Writing
Strengthen your writing with foundational grammatical rules.
How to use this guide: Start with the linked sub-guides that match your confusion first, especially Subject-Verb Agreement, Run-On Sentences, Sentence Fragments.
Start with Subject-Verb Agreement, then tackle Run-On Sentences and Sentence Fragments for the most common structural errors.
The Foundation of Clear English Writing
Every English sentence is built on a small set of structural rules. When these rules break, the meaning breaks too — no matter how good the vocabulary or ideas. A subject that disagrees with its verb, a dangling modifier, or a missing comma can turn a professional document into a confusing mess.
This collection organizes the 17 most important sentence-level rules into one reference. Whether you're writing an essay, a business report, or a creative piece, these fundamentals apply universally. Master them once, and your writing improves everywhere.
Essential Rules at a Glance
| Category | Key Guides | What You'll Learn |
|---|---|---|
| Agreement & Structure | Subject-Verb Agreement, Parallel Structure | Making subjects and verbs match; keeping lists and comparisons grammatically balanced |
| Sentence Errors | Run-On Sentences, Sentence Fragments, Dangling Modifiers | Fixing the three most common structural mistakes in writing |
| Parts of Speech | Nouns, Verbs, Adjectives | Understanding the building blocks that every sentence depends on |
| Verb Tenses | Tense Consistency, Conditional Sentences, Passive Voice | Keeping tenses aligned and choosing active vs passive voice |
| Word-Level Rules | A vs An, Good vs Well, Capitalization | Articles, adverb/adjective choice, and proper capitalization |
Where to Start
If you're unsure which rule to review first, try this priority order:
- Subject-Verb Agreement — The #1 grammar error in English writing
- Run-On Sentences — The most common structural mistake
- Comma Rules — See our Punctuation Guide for the full set
- Tense Consistency — Essential for longer documents
Each guide below uses the Answer First pattern: you get the rule immediately, then examples, common mistakes, and a practice quiz.
📚 Guides in This Collection
Subject-Verb Agreement
Find the TRUE subject. Match the verb.
→Run-On Sentences
Not about length — about joining clauses.
→Sentence Fragments
Subject + Verb + Complete thought = Sentence.
→Dangling Modifiers
Who is doing the action? Match the subject.
→Parallel Structure
Same form for items in lists and comparisons.
→Relative Clauses
Restrictive vs Non-restrictive. Commas change meaning.
→Capitalization Rules
Specific = capitalize. General = lowercase.
→Which vs That
Essential info (that) vs Extra info (which).
→Frequently Asked Questions
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