When one clause has "have", what should the other clause in the same sentence have?

Question

Consider this sentence: "Why does “singer” have /ŋ/ and “longer” have /ŋg/?"

In this sentence, "Why does “singer” have /ŋ/" is a separate clause having "does" refer to "have" (does + have).

"“longer” have /ŋg/" is a separate clause. But I am not certain about the "have" in the second clause. I rephrased the sentence as: "Why does “singer” have /ŋ/ and “longer” has /ŋg/?" but it doesn't sound right to me.

Can the first does also refer to the second clause? If so, how?

What else could I write to avoid two haves or have and has? Is my sentence correct?

Answer 1

Your original sentence is correct.

This is an example of parallelism. If you wrote it out in full you would need to repeat "why does". English grammar often allows for repeated phrases to be deleted in the second phrase, but other words should be written as if they were there.

So in full

Why does “singer” have /ŋ/, and why does “longer” have /ŋg/?

becomes

Why does “singer” have /ŋ/ and “longer” have /ŋg/?

When the parallel phrase "why does" is removed.

You could go further and also remove have.

Why does “singer” have /ŋ/ and “longer” /ŋg/?

But now there are two different deletions at two places and it is that much harder to understand (your brain needs to work harder to put "why does" in before "longer" and "have" after it.) So your original sentence is the best compromise between being short and being easy to understand.