In a recent blog entry, Jeff Atwood quotes his sysadmin Kyle:
"Should the developers have access to the production environment, and if they do, to what extent?"
My understanding is that this sentence is only perfectly grammatical if it's parsed as:
"Should the developers have access to the production environment, and if they do [already have access to the production environment], to what extent [is it okay for them to have it]?"
However, that is not what Kyle is actually asking. It's fairly obvious that he expects the question to be parsed as:
"Should the developers have access to the production environment, and if they
do[should], to what extent?"
And sure enough, that's exactly how I parsed it when I first read it. As in, I didn't even blink at the "do" kicking out a modal verb. It was only upon reading the sentence for a third or fourth time that it struck me as odd. It should also be noted that Kyle is a native speaker. So the construction can't be that ungrammatical after all, does it? Must we correct Kyle, and if we don't, why?
Edit: some of the people who have answered/commented say that they do, in fact, read Kyle's question as:
- Should the developers have access to the production environment?
- If they already have access, to what extent is it OK for them to have it?
It looks like I have to explain why this reading makes little sense — at which I only hinted above — even when no context whatsoever is provided (and Kyle's post is well over a thousand words long).
This interpretation means that if developers already have access, the first question doesn't apply. We will throw it away just for them. But the first question is universal, it must not be thrown away. It is more general, more important. If we come to the conclusion that developers, in general, should not have access to the production environment, it also applies to those developers who already do have access. In fact, it applies to them more than to anyone else.
So, Kyle cannot possibly be asking: "Should the developers have access to the production environment? Oh, and if your developers already have access, never mind, forget that question, let's just discuss how much access is okay." Much rather, he is asking: "Should the developers have access to the production environment? And if and only if the answer to that question is 'yes', how much access should they have?"