Why is John washing the car but isn’t David?

[White Hat]

The use of "is" is very common in that sort of question. (See below.)

Why is he doing that?
Why is that?
Why is it so expensive?
Why John not here?
Why is it wrong?
Why is there so much water in there?
Why is it so dark in here?
Why is it your name White Hat?
Why is there so much left?
Why is there a hat on the table?
Why is it called that?

I certainly know that. I've been trying to draw your attention to this -> 'Why is John washing the car and David isn't?'. We say 'why is John ... ?', but for some reason it is 'why ... david isn't?'. Isn't 'is' supposed to precede the subject in a 'why' question in English? That's what looks somewhat strange to me here.

 

[White Hat]

Are you suggesting that 'Why David isn't?' is correct as a question?

 

[Tarheel]

Are you suggesting that 'Why David isn't?' is correct as a question?

No, I'm not, and it isn't.

 

[White Hat]

No, I'm not, and it isn't.

That's what I'm trying to draw your attention to. Let's take another look at it: 'Why is John washing the car and David isn't?'. Split it into two parts: 'Why (1) is John washing the car and (2) David isn't?'. What I want to know is why in the first part of this question 'is' precedes the subject ('John') but follows the subject ('David') in the second.

 

[White Hat]

We wouldn't normally ask 'Why John is washing the car and David isn't?', would we?

 

[5jj]

In 'Why is John washing the car and David isn't?' we have one why question - I've underlined it. The part that is not underlined is not a question.
In 'Why is John washing the car, and why isn't David doing so?' we have two why questions,

 

[White Hat]

In 'Why is John washing the car and David isn't?' we have one why question - I've underlined it. The part that is not underlined is not a question.

Isn't the part that's not underlined part of one complex question?

 

[Tarheel]

We wouldn't normally ask 'Why John is washing the car and David isn't?', would we?

No. In fact, I posted something to illustrate a more natural way of saying that.

Have you seen that post? (#16)

 

[White Hat]

Have you seen that post? (#16)

That I have absolutely no problem with.

 

[5jj]

Isn't the part that's not underlined part of one complex question?

No. It is an additional piece of information.

 

[Tarheel]

Isn't the part that's not underlined part of one complex question?

My opinion is the entire sentence is a question, but that part is not.

 

[jutfrank]

We wouldn't normally ask 'Why John is washing the car and David isn't?', would we?

I can see what's troubling you is that there appear to be two sentence types conjoined here: the first interrogative and the second declarative.

Why is John washing the car
and
David isn't (washing the car)

I totally understand how this seems incorrect/illogical to you but it's really quite natural.

Still, like you, I don't much like it. Both logically and grammatically, I prefer:

Why is it that
John is washing the car and David isn't (washing the car)

Not only is this cleft version logically more elegant, it also expresses the meaning better, in my opinion, since the 'it' places a focus on the situation itself, i.e., that an unexpected man is washing the car.

Even better would be Why is John washing the car and not David?

 

[emsr2d2]

Even better would be Why is John washing the car and not David?

That leaves open the possible, if unlikely, ambiguity that I mentioned earlier in the thread. It could be taken to mean "Why is John washing the car instead of washing David?"

 

[White Hat]

That leaves open the possible, if unlikely, ambiguity that I mentioned earlier in the thread. It could be taken to mean "Why is John washing the car instead of washing David?"

I agree with you, but I also think that could be resolved via stressing each of the names.

 

[jutfrank]

That leaves open the possible, if unlikely, ambiguity that I mentioned earlier in the thread. It could be taken to mean "Why is John washing the car instead of washing David?"

Yes, as written, it's ambiguous.

I agree with you, but I also think that could be resolved via stressing each of the names.

Exactly right. In speech, the ambiguity would be resolved.

 

[Tarheel]

I agree with you, but I also think that could be resolved via stressing each of the names.

In theory that one is ambiguous. In practice it's not.

 

[Holmes]

A: Why is John washing the car but isn’t David?

While I agree with others that (A) is ungrammatical, I don't see the problem as being whether to use "but isn't David" or "but David isn't" at the end of the question. First, "but" is not as central a coordinator as "and" is, and this can easily become apparent when ellipsis is involved, as it is here. I think that "and" works much better here than "but."

Second, instead of saying "and not David" or "and David isn't," it would be better to say "and David not." By the time "is" moves to the front of the question, beneath "why," it does so in the company of the second "is," the two verbs becoming one at that stage of the transformational derivation of the sentence. We can even see this in the full version of the sentence, without ellipsis:

Why is John washing the car and David not?
Why is John washing the car and David not washing the car?

Note that this phenomenon will only be observed with the first auxiliary verb in the stack of auxiliary verbs, if there is more than one:

Why has John been washing the car and David not been?
Why has John been washing the car and David not been washing the car?