Do your brother work in a hospitalis this sentence correct?

The sentence "Do your brother work in a hospital?" is incorrect. The correct form is "Does your brother work in a hospital?"

In the English language, the verb "do" is used in the present tense with the pronouns "I," "you," "we," and "they." The verb "does" is used in the present tense with the pronouns "he," "she," and "it."

Therefore, since the subject of the sentence is "your brother," which is a third-person singular pronoun, the correct verb to use is "does."