Exactly what

[John]

Are these both correct? If so, which is common?

1. What do you mean exactly?
2. Exactly what do you mean?

Thanks.

[Rusty]

Are these both correct? If so, which is common?

1. What do you mean exactly?
2. Exactly what do you mean?

Thanks.

They are both natural and both common. I think 2. is more formal.

[John]

> 1. What do you mean exactly?
In this sentence, what does "exactly" modify?
Is it "what" or "mean"?

Thanks.

[Pete]

> 1. What do you mean exactly?
In this sentence, what does "exactly" modify?
Is it "what" or "mean"?

Thanks.
I think it modifies the whole thought, "what do you mean?". All the dictionaries that I looked in called it an adverb, so I don't think it can modify "what", even though is some ways that would seem plausible.