A member stated that "all" in such a sentence as "All (that) I want is your respect" is, loosely speaking, the object of "want." Would someone kindly explain the grammatical analysis involved. Thank you.
Ooh, I know this one. 'All I want' is a noun phrase, the subject of 'is'. It's headed by 'all', however, which is not a noun but a determinative. The CGEL (Cambridge Grammar) analyses it as a fused head here: it is both the determiner of the noun phrase (as it is with a noun, as in 'all things') and the head (what the noun is when there is a noun). The CGEL prefers this analysis to one in which 'all' is converted to a different category (traditionally pronoun).
Whether pronoun or fused head, the next point is that it isn't actually the object of 'want'. There's a matrix clause 'All <relative clause> is . . .', and the word 'all' is in that. It isn't in the relative clause 'I want', so it can't be the object of it: object is a syntactic (structural) notion, not a semantic one. The entire relative clause is 'I want', and 'want' is a transitive verb, but obviously it has no overt object.
Now we get theoretical. Let's say there is a gap where the object should be: the clause is 'I want __'. Or it could be called a trace, 'I want t', where t is phonetically empty but actually serves a grammatical function. Now as this is a relative clause, there is often a relative marker at the front - either a relative pronoun ('the thing [which I want t]') or the subordinator 'that' ('the thing [thate I want t]', where e indicates another phonetically empty element in the same position as 'which' - traditionally 'that' is analysed as a pronoun like 'which', but it's not).
These are co-indexed: they are interpreted the same way. If they refer to anything, they refer to the same thing. So let's add indices: 'the thing [which-i I want t-i]'.
This indexing is inside the relative clause. But of course these elements of this clause also co-refer (are co-indexed) with an element of the matrix clause - that's what relative clauses do. So add another index: 'the thing-i [which-i I want t-i]'.
To conclude, the actual object of 'want' is a trace that's co-indexed with an element at the front of the relative clause, which is coindexed with the antecedent in the matrix clause. In the original example, this antecedent is 'all', whether that's a fused-head determinative or a pronoun. It bears the same semantic relationship to 'want' as the overt object does in 'I want chocolate'. (Technically, the stimulus, I think.) It's just that, as it's a semantic rather than syntactic relationship, we shouldn't call it object.
Thank you very much for your explanation about the role of "all" in "All that I want is your respect." I shall slowly and carefully study your words. Even though it involves more than traditional high school grammar, I am sure that I shall be able to understand some of it.