1. Subject-Verb Agreement: Ensure that the subject and verb in a sentence agree in number. For example, “She walks” (singular) vs. “They walk” (plural).
2. Punctuation: Use proper punctuation marks, such as periods, commas, semicolons, colons, question marks, and exclamation points, to clarify sentence structure and meaning.
3. Capitalization: Capitalize the first letter of sentences, proper nouns (e.g., names, places), and the pronoun “I.”
4. Grammar Tenses: Use appropriate verb tenses (past, present, future) consistently within a sentence or paragraph.
5. Word Order: Follow the standard word order for English sentences: subject-verb-object (SVO). For example, “She (subject) eats (verb) apples (object).”
6. Articles: Use articles (“a,” “an,” “the”) correctly. “A” and “an” are used with singular, non-specific nouns, while “the” is used with specific nouns.
7. Plurals: Add “s” to most nouns to make them plural (e.g., dog/dogs), but be aware of irregular plurals (e.g., child/children).
8. Possessives: Use apostrophes to indicate possession (e.g., John’s book). Ensure correct usage of possessive pronouns (e.g., his, her, their).
9. Prepositions: Use prepositions (e.g., in, on, under) to show relationships between words and indicate location or direction.
10. Conjunctions: Use conjunctions (e.g., and, but, or) to connect words, phrases, or clauses in a sentence.
11. Verb-Adjective Agreement: Ensure adjectives agree in number with the nouns they modify (e.g., a red car, two red cars).
12. Double Negatives: Avoid using double negatives, as they can create confusion. For example, instead of “I don’t need no help,” say “I don’t need any help.”
13. Sentence Structure: Craft clear and concise sentences with a subject, verb, and, if needed, an object. Avoid sentence fragments and run-on sentences.
14. Parallel Structure: Use parallel structure when listing items or ideas in a sentence (e.g., “She likes to swim, hike, and bike”).
15. Modifiers: Place modifiers (adjectives and adverbs) next to the words they modify to avoid ambiguity.
16. Spelling: Spell words correctly, and be mindful of homophones (e.g., their/there/they’re, to/too/two).
17. Contractions: Use contractions (e.g., don’t, can’t, won’t) in informal writing and speech but avoid them in formal writing.
18. Hyphens and Dashes: Use hyphens to connect compound words (e.g., well-known) and em dashes to set off parenthetical information.
19. Quotation Marks: Use quotation marks to enclose direct speech or when citing titles of short works (e.g., “The Catcher in the Rye”).
20. Subject Pronoun/Object Pronoun: Distinguish between subject pronouns (e.g., I, he, she) and object pronouns (e.g., me, him, her) based on their roles in the sentence.

Remember that language rules may vary slightly in different English dialects and contexts, so it’s important to consider the specific audience and purpose of your writing or communication.