Which is correct..

Who does the play have as its star?

or

Whom does the play have as its star?

Thank you.

If you turn the sentence around to make it a statement, the correct pronoun should be clear.

The does have _____ as its star.

whom

Right.

I see I left "play" out of my sentence.

Both versions of the question can actually be correct, but they have slightly different grammatical structures.

The first version, "Who does the play have as its star?" is using the pronoun "who" as the subject of the verb "does have." In this sentence, "who" is functioning as a subject pronoun.

The second version, "Whom does the play have as its star?" is also grammatically correct. In this sentence, "whom" is functioning as an object pronoun, as it is the object of the verb "does have."

To determine whether to use "who" or "whom," you can try rephrasing the sentence and see which pronoun sounds more appropriate. For instance, you could rephrase the question as "The play has [who/whom] as its star?" If "who" sounds better, then use "who" as the pronoun (as in the first version). If "whom" sounds better, then use "whom" (as in the second version).

It's worth noting that in modern English, the use of "whom" is becoming less common and is typically reserved for more formal or careful speech. In everyday conversations, many people would use "who" in place of "whom" in both subject and object pronoun positions.

So, in summary, both versions can be correct, but the first version using "who" as the subject pronoun is more commonly used in modern English.