When asking questions about the subject part, if the subject is plural, does the be verb use the singular or the plural? Who is your brother or who are your brothers?

When asking questions about the subject part, if the subject is plural, does the be verb use the singular or the plural? Who is your brother or who are your brothers?

Who is your brother?

When the subject is the third person singular (negative sentence), should the verb be singular or plural?
For example: Mrs.White Don't (take or take?) a show in the afternoon

Take doesn't

Is the verb after "neither subject nor subject" singular or plural?
Neither subject nor subject,
Either subject or subject
What is the form of the following verbs? For example, is or are, takes or take?
Is it right to use plural form after both subject and subject, such as both she and I are studnet?

Neither subject nor subject,
The principle of proximity is applied to either subject or subject, which is consistent with the subject after nor and or
Both subject and subject must be plural
eg.Either Danny or I am going with you.
Neither Danny nor I am going with you.
Both Danny and I are going with you.