Subjects and verbs must agree in number.
Example: The team is winning. The players are excited.
Pronouns must agree with their antecedents.
Example: Every student must bring his or her book.
Use commas to separate items in a list and after introductory phrases.
Example: After dinner, we watched a movie.
Place modifiers near the word they modify.
Incorrect: Walking home, the rain soaked her.
Correct: Walking home, she was soaked by the rain.
Use the same grammatical form in lists.
Example: She likes swimming, biking, and running.
Keep verb tenses consistent.
Incorrect: He starts the car and drove away.
Correct: He started the car and drove away.
Use apostrophes for possession and contractions.
Example: That's Sarah's book. It's a nice day.
Do not use two negatives in one sentence.
Incorrect: I don't need no help.
Correct: I don't need any help.
Use semicolons to link related independent clauses; colons to introduce lists.
Example: She has three hobbies: painting, dancing, and reading.
Ensure comparisons are logical and complete.
Incorrect: She is smarter than anyone in her class.
Correct: She is smarter than anyone else in her class.
