In nonstandard and casual speech, the -s verb form has, does, or doesn’t is sometimes replaced with have, do, or don’t. In standard English, use has, does, or doesn’t with a third-person singular subject.
Present-tense forms of do (including negative forms)
Present-tense and past-tense forms of have
When to use the -s (or -es) form of a present-tense verb
Exercise: Standard English verb forms 1
Exercise: Standard English verb forms 2
Exercise: Standard English verb forms 3
Exercise: Verb tense and mood 1
Exercise: Verb tense and mood 2
Exercise: Verb tense and mood 3