What are some common grammatical errors in English?

Sure, here are some common grammatical errors in English:

• Subject-verb agreement: This is the most common grammatical error in English. It occurs when a verb does not agree with its subject in number (singular or plural). For example, the sentence "I read a book yesterday" is correct, but the sentence "I read a books yesterday" is incorrect.
• Pronoun-antecedent agreement: This error occurs when a pronoun does not agree with its antecedent in number (singular or plural). For example, the sentence "I saw her yesterday" is correct, but the sentence "I saw her yesterday" is incorrect.
• Verb tense consistency: This error occurs when a verb is used in a different tense than the one required by the context. For example, the sentence "I went to the store yesterday" is correct, but the sentence "I went to the store last night" is incorrect.
• Dangling modifiers: These are modifiers that are misplaced and do not modify the correct word. For example, the sentence "The dog that I love is a golden retriever" is correct, but the sentence "The dog that I love is a golden is a golden retriever" is incorrect.
• Misuse of articles: Articles are used to indicate the possession of a noun, but they can also be used incorrectly. For example, the sentence "I have a book" is correct, but the sentence "I have the book" is incorrect.
• Misuse of prepositions: Prepositions are used to show the relationship between a noun and another, but they can also be used incorrectly. For example, the sentence "I went to the store on Monday" is correct, but the sentence "I went to the store on Monday morning" is incorrect.
• Misuse of conjunctions: Conjunctions are used to connect two or more words, phrases, or clauses, but they can be used incorrectly. For example, the sentence "I went to the store and I bought some groceries" is correct, but the sentence "I went to the store and I bought some groceries, and I also bought some milk" is incorrect.