Question about questions.

I posted this in the wrong place earlier, probably. So, I'll try here.

1. "What do you think is the best American novel?"

2. "What do you think the best American novel is?"

I know which one sounds better. But is the first one incorrect for any reason? I don't think it is, but someone I work with does. Am I wrong? Any thoughts would be appreciated. Thanks.

#2 is the more standard form, but most speakers would consider either acceptable.

In the first, 'what' is essentially treated as a substitute for 'which', which may function either as subject or as complement, allowing us, for instance, to point at a person in a photograph and ask either

Which (one) are you?

('You' as subject and 'which' as complement)

or

Which (one) is you?

('which' as subject and 'you' as complement)

with no appreciable difference of meaning.

Thank you. That was very helpful.