Determiner or pronoun

Persian LearnerHi.Much of the work has already been completed.Is much in the above sentence a determiner or pronoun? Why?

It is the subject of that sentence. What you you think?

What about this one?
Much work has already been completed.

I agree with you dear teacher, but why has Macmillan Dictionary said the opposite?

AlpheccaStarsIt is the subject of that sentence. What you you think?

I think the whole phrase: much of the work is the subject.

Persian LearnerI agree with you dear teacher, but why has Macmillan Dictionary said the opposite?

I didn't write the Macmillan Dictionary.

See entry #2;
http://www.dictionary.com/browse/much?s=t

AlpheccaStarsI didn't write the Macmillan Dictionary.

I see.

Persian Learner much of the work is the subject.

Do you agree that "of the work" is a propositional phrase? And "work" is the complement (object) of the proposition "of"?

AlpheccaStarsDo you agree that "of the work" is a propositional phrase? And "work" is the complement (object) of the proposition "of"?

100%

Kindly look at the following sentences:

1) The name of the street is unknown.

2) Much of the money has been spent.

3) Much has already been received.

What's the form and function of The name in the first sentence? I think its form is noun phrase and its function is determiner, right?

In the second sentence, the form

Persian LearnerIs my deduction correct?

No.
You need to understand the definition of "determiner" in linguistics.

https://en.wikipedia.org/wiki/Determiner A determiner, also called determinative (abbreviated det), is a word, phrase, or affix that occurs

1) The name of the street is unknown.

Persian LearnerWhat's the form and function of The name in the first sentence? I

The form class of "The name" is the noun phrase where "name" is a noun and the head of the noun phrase and "The" a determiner (form class) and modifier (function) of The head of the phrase.
The function