A question on English usage: In the sentence below, which form of the verb "have" should be used?

Ok. It's been a long time since high school grammar class, but I'll give it a go.

'Any' is an indefinite pronoun. Indefinite pronouns by definition reference nonspecific things or people.

The problem is that 'any' is one of the indefinite pronouns that can be considered either singular or plural.

No help, right?

Ok. Let's analyze:The use of 'any' in front of a singular noun talks about EACH thing or person of a particular type. The use of 'any' in front of a plural noun talks about ALL things or people of a particular type.

To get back to your sentence: Since it says 'never', I'm going with the idea that 'any' refers to ALL.

So - There have never been any very convincing definitions of illness, disease or mental disorder.

That's how I'd put it.

HAVE is the correct usage, because the way the sentence is written it brings up a mental picture of things having taken place already (the past).

To use HAS, take out the word very (There has never been any convincing definitions...)

If you take ABANDONED CHILDREN as the subject it would be IS because this would imply they are talking about one problem in particular, that issingular. In the case children is the subject it is a plural so you need to use ARE concern in this case is the noun. It is not used as verb here. (in order to useit as verb u should say The agency is concerned about abandoned children). children is the subject ("who is the main concern?) abandoned childre ARE the main concern of the agency, or , The problem of abandoned children IS the main concern... In this case problem becomes the subject to say it in an easy way.

Neither will make the sentence correct -- it doesn't use proper grammar because "any" refers to something singular but "definitions" is plural. The sentence should read one of two ways:

"There have never been very convincing definitions of illness, disease or mental disorder."

"There has never been any very convincing definition of illness, disease or mental disorder."

Have....the word definitions is plural

You should use the verb "has".

...why are you asking if you already know the answer?

"have." "definitions is plural, and is the object of the conjugation.

Have. It's plural.

Have

The word is "have"!