grammar - Why is "there" a subject while "here" isn't?

The question about "the role of infinitive in this sentence" prompted me to ask the following question.

English uses a "dummy" such as it and there to start a sentence when there is nothing else to start an extra-posed sentence in the linked question or a sentence starting with "there". Please read the comments below the answer.

I object to calling "there" a subject of the sentence in the following:

There is a man at the door.

There is redundant as it could be rephrased to "A man is at the door/A man is there (pointing at the door)" as "at the door" indicates the place where a man physically exist at this moment. Here, "there" is a dummy which means nothing.

Another example:

There was no snow yesterday.

In this sentence, there means nothing and just indicates the existence of "snow" yesterday.

Oxford Online Dictionary classifies this dummy "there" as an "adverb"

3 (usually there is/are) Used to indicate the fact or existence of something: ‘there’s a restaurant round the corner’

Let's say two people are engaged in a phone conversation:

A: There was much snow yesterday in our town. Was there much snow?
B: Here was not much (snow).

If "there" in the abvoe is a subject as a dummy, why is "here" not a subject?

Note: I read the linked previous question with an interest but it doesn't address why "here" cannot be a dummy subject like dummy there.

Answer

I wouldn’t go along with that. Locative “there” is an adverb (some grammars call it a prep) rhyming with “dare” and meaning “in or at that place”. Dummy pronoun “there” on the other hand is pronounced unstressed with a reduced vowel and used to fill the syntactic subject position in existential clauses. So there is a difference in category, pronunciation and meaning.

Historically, dummy pronoun “there” derives from the locative “there”, but it has been bleached of its locative meaning and reanalysed as a pronoun.

The point is that the dummy pronoun “there” is without doubt the syntactic subject in an existential clause, no less than “it” is the subject in an extraposed construction. This can easily be proved:

1. 
   

   “There” occupies the basic subject position before the verb, e.g. “There was a nurse present”.

   
   


2. 
   

   In subject-auxiliary inversion constructions it occurs after the auxiliary, e.g. “Was there a nurse present?”

   
   


3. 
   

   “There” occurs as subject in interrogative tags, e.g. “There was a nurse present, wasn’t there”?

   
   

Yes, the Oxford Online dictionary does indeed give existential “there” as an adverb, but it is wrong! As usual, it is just using ‘adverb’ as a classificatory dumping ground for any word that doesn’t easily fit into one of the other word categories. The examples above demonstrate without doubt that existential “there” is a pronoun. In any case, the function of subject can’t normally be realised by an adverb.

To complete the syntax, the subject of the non-existential construction becomes a displaced subject in the existential version:

[1] "Several windows were open". [2] "There were several windows open".

In [2] “several windows” is analysed as a displaced subject (an internal complement of the verb), but it does correspond semantically to the subject in the non-existential counterpart [1].

Finally, you asked why "here" could not be the subject in:

"Here was not much snow".

"Here" is not a pronoun here, but an adverb (some call it a prep) so it can't possibly be subject. The syntactic subject in this example is "not much snow", and "here" is locative predicative complement. Think of it as "Not much snow was here". As further evidence, note that inversion would not be possible, *"Was here not much snow"?