Which one is correct? "People who have a toothache go to the dentist" or "People who have toothaches go to the dentist"?

Question

I asked a similar question on another Q&A website and got different answers from native speakers. Some of them even said I shouldn't use "a" before toothache and backache, but some said I should. It seems to be a regional variation.

The question is do we make headache, toothache, etc plural in accordance with the subject or do we use the singular form at all times? Consider the following examples:

"The children have a toothache / a headache / a backache / an earache / a running nose"

vs.

"The children have toothaches / headaches / backaches / earaches / running noses"

Which one is grammatically correct?

P.S. In my example sentence, when we say people go to the dentist, are we talking about dentists in general or are we talking about a specific dentist?

Answer 1

There is no rule that covers all situations.

It is as natural and correct to say they both had a headache after the party as they both had headaches after the party.

In general, people suffer from headaches/migraines (plural) and from toothache/backache (singular). But that's not a rule. The choice of singular or plural depends on preference, context and sentence construction.

If you go to the dentist, unless you have previously specified which dentist, you go to any dentist. Expressions such as going to the shops, dentist, doctor, lawyer and so on are used to indicate intention rather than to identify the place or individual concerned.