Regarding this sentence that you presented:
“President Benigno Aquino 3rd’s economic managers today will present before him and later the Senate their scenarios on the possible impact of the US and Euro zone debt crises on the Philippine economy.”
The problem is its ill-advised use of the preposition “before” in the sense of “to” and the unparallel compounding of two objects of the preposition, making the statement very confusing. And this confusion arises not because the objects of the preposition in that sentence are a pronoun (“him”) and a noun (“the Senate”). Indeed, their being different parts of speech absolutely has got nothing to do with the awkwardness of that sentence construction.
Note that in that sentence, “before” is being used in the sense of “in front of” or “in the presence of.” Although a grammatically valid usage, that preposition really doesn’t yield the precise meaning intended by that statement. This is because usually, ‘before” evokes the sense of an individual or just a few persons doing something or performing in front of or in the presence of an audience much bigger in size than that of the presentor or presentors. “Before” doesn’t seem to work as well when the number of presentors far outnumbers an audience of only one. We therefore expect to read sentences like “The President presented his five-year plan before a joint session of the Senate and House of Representatives,” but will find it very odd indeed to read sentences like “The joint session of the Senate and House of Representatives presented the sentiments of Congress before the President.” English just doesn’t work that way! In such cases, the preposition “to” is used for clarity. It’s a word choice that also avoids being misinterpreted as the adverb “ahead” or “earlier than.”
In sentences that use an intransitive verb like “present” and where there are two or more objects of the preposition, it’s highly advisable to use only one common preposition. This is a good way to maintain parallelism of the grammatical structures and make them read properly. In the case of the sentence in question, however, this parallelism prescription is violated by the clause “President Benigno Aquino 3rd’s economic managers today will present before him and later the Senate their scenarios…” For parallelism to be achieved in that sentence, there must be another “before” between the word “later” and “the Senate,” as follows: “President Benigno Aquino 3rd’s economic managers today will present before him and later before the Senate their scenarios…”
But we can see right away how awkward and confusing that sentence construction is! The culprit, of course, is the use of “before,” which as I explained earlier was ill-advised. See how nicely and clearly everything falls into place when we replace “before” with “to” and use it before each object of the preposition (“him” and “the Senate”):
“President Benigno Aquino 3rd’s economic managers today will present to him and later to the Senate their scenarios on the possible impact of the US and Euro zone debt crises on the Philippine economy.”
This is also why it is very important to compound two objects of the preposition in parallel, as in this case. It takes out the rough edges from the sentence and makes it read much more clearly and smoothly.
