Here are some examples of basic grammar rules:

1. Subject-verb agreement: The subject and verb in a sentence must agree in number (singular or plural). For example:

• Incorrect: The group of students was arguing.
• Correct: The group of students were arguing.

In the incorrect example, “was” is singular, but “group of students” is plural. The correct version uses “were” to match the plural subject.

2. Pronoun-antecedent agreement: A pronoun (like he, she, it, they) must match the noun it refers to (its antecedent) in number and gender. For example:

• Incorrect: Each student must bring their own lunch.
• Correct: Each student must bring his or her own lunch.

In the incorrect example, “their” is plural, but “student” is singular. The correct version uses “his or her” to match the singular antecedent.

3. Verb tenses: The verb tense in a sentence should be consistent and match the time frame of the action being described. For example:

• Incorrect: She finished her homework and then she will watch TV.
• Correct: She finished her homework and then watched TV.

In the incorrect example, “will watch” is future tense, but the action is happening in the past. The correct version uses “watched” to match the past tense of “finished.”

4. Parallel structure: When listing items in a sentence, they should be in the same grammatical form. For example:

• Incorrect: She likes hiking, swimming, and to run.
• Correct: She likes hiking, swimming, and running.

In the incorrect example, “to run” is not in the same form as “hiking” and “swimming.” The correct version uses the -ing form of “run” to match the other items in the list.

5. Misplaced modifiers: A modifier (like an adjective or adverb) should be placed next to the word it modifies. For example:

• Incorrect: The boy found the toy in the store that was broken.
• Correct: The boy found the broken toy in the store.

In the incorrect example, “that was broken” modifies “store” instead of “toy.” The correct version moves the modifier next to “toy” to make the sentence clear.

6. Pronoun case: The form of a pronoun depends on its role in the sentence (subject or object). For example:

• Incorrect: Him and me went to the store.
• Correct: He and I went to the store.

In the incorrect example, “him” and “me” are object pronouns, but they are used as the subject of the sentence. The correct version uses the subject pronouns “he” and “I.”

7. Pronoun reference: A pronoun should clearly refer to a specific noun or antecedent in the sentence. For example:

• Incorrect: The dog chased the cat, and it ran up a tree.
• Correct: The dog chased the cat, and the cat ran up a tree.

In the incorrect example, “it” could refer to either the dog or the cat, making the sentence unclear. The correct version uses “the cat” to clearly refer to the antecedent.

8. Comma usage: Commas should be used to separate items in a series, set off introductory phrases, and separate independent clauses in a compound sentence. For example:

• Incorrect: We went to the park, played basketball and had a picnic.
• Correct: We went to the park, played basketball, and had a picnic.

In the incorrect example, there is no comma between “basketball” and “and,” making the sentence unclear. The correct version uses commas to separate all items in the series.

9. Adverb placement: Adverbs should be placed next to the verb they modify or at the beginning or end of a sentence. For example:

• Incorrect: The dog barked loudly, waking up the baby in the crib.
• Correct: The dog loudly barked, waking up the baby in the crib.

In the incorrect example, “loudly” is separated from the verb it modifies, making the sentence unclear. The correct version places “loudly” directly next to “barked.”

10. Active vs. passive voice: In active voice, the subject performs the action of the verb. In passive voice, the subject receives the action of the verb. Active voice is usually preferred for clear and concise writing. For example:

• Passive: The cake was baked by my mom.
• Active: My mom baked the cake.

In the passive example, “the cake” is the subject, but it is not performing the action of the verb “baked.” The active version makes the sentence clearer by putting the subject (“my mom”) before the verb.

11. Relative clauses: A relative clause provides additional information about a noun or pronoun in the sentence. It begins with a relative pronoun (like who, whom, whose, which, or that) and is usually separated from the rest of the sentence by commas. For example:

• The book, which was written by a famous author, won many awards.

In this example, “which was written by a famous author” is the relative clause that provides additional information about “the book.”

12. Sentence variety: Varying the length and structure of sentences can make writing more interesting and engaging. For example:

• Short: The cat meowed.
• Medium: The cat meowed loudly, demanding attention from its owner.
• Long: The cat, a sleek Siamese with piercing blue eyes, meowed loudly and persistently, demanding attention from its distracted owner who was lost in thought.