Overthinking "...expect there to be..."

Question

This sentence struck me as odd when I casually said it in conversation:

I expect there to be bears.

...meaning I wanted [sarcastically] bears in the cave we were planning on exploring. What allows for the odd construction of "...expect there to be..."?

I scoured the internet, found an EL&U question, found another EL&U question, and discussed with my friends to no avail. Well, to some avail, but I'm still left with questions regarding construction, and how many grammar rules I'm bending or making up.

• The word "expect" always takes an infinitive clause (never a gerund [why?]), which explains the "to be". Could we say that "to be expected" is a verb phrase?
• I think "there" is an Adverbial Demonstrative Pronoun. Adverbial because it's supporting a verb and Demonstrative Pronoun because it's replacing the known noun phrase (the cave). I'm having a hard time backing this up with sources though.
• If "there" is adverbial, what verb is it supporting: "expect" or "to be"? Or, is it an entire verb phrase as I mentioned ("to be expected") that's been flip-flopped and split by "there", thus making "there" support both? (I feel like I just made that up but can't find evidence otherwise.)
• My friend said "there" is a post-position, because it's after the verb (he's assuming it's supporting "expect") but I read post-positions are not common in English.

Perhaps this is a daft and overthought, unimportant question, but it's been bugging me so I'm hoping for a smarter person to help with an explanation of this construction.

(A side thought, possibly unrelated, but regarding redundancy: If "there" means "the cave", I can say "I expect bears to be in the cave." ("I expect bears to be there.") This has the same meaning as my original sentence, but re-arranged. But I could even say "I expect there to be bears in the cave" or "I expect there to be bears there" which, to me, makes "there" redundant but still grammatically correct. Why?)

Answer 1

I don't think expect always takes an infinitive clause. Here's the definition from the Oxford Dictionaries:

expect

VERB

[WITH OBJECT]

1. Regard (something) as likely to happen.

   ‘it's as well to expect the worst’

   [with object and infinitive] ‘the hearing is expected to last a week’
   [with clause] ‘one might expect that Hollywood would adjust its approach’

   1.1 Regard (someone) as likely to do or be something.

   [with object and infinitive] ‘they were not expecting him to continue’

   1.2 Believe that (someone or something) will arrive soon.

   ‘Celia was expecting a visitor’

   1.3 Require (something) as rightfully due or appropriate in the circumstances.

   ‘we expect great things of you’

   1.4 Require (someone) to fulfil an obligation.

   [with object and infinitive] ‘we expect employers to pay a reasonable salary’

   1.5 (I expect) informal Used to indicate that one supposes something to be so but has no firm evidence.

   ‘they're just friends of his, I expect’
   [with clause] ‘I expect you know them?’

Note especially definition 1.5 -- this is the version you used.

So what you're really saying is my expectation is that there will be bears [in the cave].

Answer 2

It seems that the OP has been put on the path of this 'overthinking' by assuming that there here refers to the cave. The puzzle, however, disappears if one takes there to play here the same role that it plays in the phrase there are, i.e. to stand for nothing in particular. (Its standing for nothing in particular, of course, does not mean that it is redundant, it is an essential part of the phrase, which, as a whole, has a definite meaning.)

To see that, let's ask ourselves how one would express the content of this expectation, without explicitly saying 'I expect'. One might say:

There will be bears in the cave.

However, if the context already makes it clear that we are discussing what will be found in the cave, one may omit 'in the cave' and say simply:

There will be bears.

Note that there in that sentence does not refer to any particular location.

Now, let's bring the words 'I expect' back into the sentence. This may give us:

I expect that there will be bears.

This is interchangeable with the original sentence:

I expect there to be bears.

If one had wanted to have a sentence in which there stands for the cave, one would have positioned it differently:

Some bears will be in the cave.

Some bears will be there.

I expect that some bears will be there.

I expect some bears to be there.

That, however, is not the sentence that the question is about.

Answer 3

//I expect there to be bears.// What is expected here? "there to be bears"? One cannot make its passive with this noun phrase, even if we consider so.

If what is expected is 'bears'? It should be "I expect bears to be there." having the PV, "Bears are expected to be there."

'Expect' is transitive, and can have person(s) or thing(s) as objects. That way,sentences are formed like, "I expect you to be there", I expect the envelope to be there." etc. Here, that also fails.

Hence, it should ideally be, "I expect bears to be there", so that readers are not left to make inferences.