Instructions: Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.
Input: Which one is correct in a sentence? He don't He doesn't I guess 'he doesn't' should be correct because he is third person singular but I've seen some people using do with he. Which one is correct?.
Output:
He doesn't is correct, because it is the contraction of He does not. He don't is incorrect, because it it the contraction of He do not. Subject-Verb agreement requires that he goes with does. He don't, however, is slang and certainly used in many places, but you would never see it in professional writing, because of Subject-Verb agreement.