"what have brought you here" vs "what has brought you here"

saraba Which is correct and why?

What has ...?

"what" is singular; it takes a singular verb.

CJ

sarabaWhich is correct?

What has brought you here?

saraba and why?

'What' is singular unless context strongly legislates otherwise. Here we expect only a single cause of attraction or mode of transportation.

CalifJim"what" is singular; it takes a singular verb.

In this case, right?

Mister MicawberIn this case, right?

Exactly. In this particular sentence, where "what" is obviously the subject.

Contrast: What are the reasons? where arguably 'the reasons' is the subject. Answer: The reasons are ....

CJ

CalifJim In this particular sentence, where "what" is obviously the subject.

What about this?—

What are your favorite cuisines?

Hmm. I now see that's a linking verb. Does that make a difference?

Mister MicawberWhat about this?—What are your favorite cuisines?

I added more to my answer.

My favorite cuisines are Indian and Italian.

CJ

Oops. We seem to be editing in tandem.

Mister Micawbera linking verb

It's rare for "what" to be a subject when followed by a linking verb, though there are some examples, none of which come to mind just now.

CJ

Ah!

What is the matter? Nothing's the matter.

Thank you very much