Only "were"?

[kiranck007]

Text:
Subgroup Modifiers
When you want to describe a part of a larger group with a modifier, use one of the following three Subgroup Modifier constructions.
Right: This model explains all known subatomic particles, SOME OF WHICH WERE only recently discovered.
Right: This model explains all known subatomic particles, SOME OF THEM only recently discovered. Right: This model explains all known subatomic particles, SOME only recently discovered.
Notice that only the which construction has a working verb (were) in it.
In contrast, wrong answer choices often include the following three incorrect constructions, which scramble the correct forms.
Wrong: This model explains all known subatomic particles, OF WHICH SOME WERE only recently discovered.
Wrong: This model explains all known subatomic particles, SOME OF THEM WHICH WERE only recently discovered.
Wrong: This model explains all known subatomic particles, SOME OF WHICH only recently discovered.

Source: GMAT, Manhattan (2012-04-24). Sentence Correction GMAT Strategy Guide, 5th Edition (Manhattan GMAT Strategy Guides) (Kindle Locations 4785-4796). Manhattan Prep. Kindle Edition.
Question One:

I understand that the working verb part is emphasized above. Could you please explain me why we can’t use "were" in any of the other right/wrong constructions provided above. Also, is it necessary to use "were" as is used in one of the right construction provided above? Also, Can’t we use any other working verb other than "were" ?

Text :

Right: She argues THAT the agency acts WITH reckless abandon AND WITH disregard for human life AND property, AND THAT it should therefore be shut down.

Source :
GMAT, Manhattan (2012-04-24). Sentence Correction GMAT Strategy Guide, 5th Edition (Manhattan GMAT Strategy Guides) (Kindle Locations 847-848). Manhattan Prep. Kindle Edition.

Questions Two:

In the above sentence, can we effortlessly say that the antecedent of "it" is "the agency", because clauses starting with "THAT" are parallel and they should be structurally similar.
Thanks,
Kiran

[rte.sushil]

adding one question:

The model explains all known subatomic particles, some of them were only recently discovered :- should also be correct? Because particles are discovered by someone not discovered by themselves.

In the similar lines,
This model explains all known subatomic particles, SOME OF THEM only recently discovered.
This model explains all known subatomic particles, SOME only recently discovered.

Why helping verb"were" is not present in above 2 sentences. They were not discovered themselves.

Please explain..

Thanks

[rte.sushil]

adding one question:

The model explains all known subatomic particles, some of them were only recently discovered :- should also be correct? Because particles are discovered by someone not discovered by themselves.

In the similar lines,
This model explains all known subatomic particles, SOME OF THEM only recently discovered.
This model explains all known subatomic particles, SOME only recently discovered.

Why helping verb"were" is not present in above 2 sentences. They were not discovered themselves.

Please explain..

Thanks

[RonPurewal]

Wrong: This model explains all known subatomic particles, OF WHICH SOME WERE only recently discovered.

actually, i don't think this one is wrong. it looks fine to me.

it's a bit wordy -- i.e., it contains more stuff than some of the other versions here that are also valid -- and it's not the most beautiful sentence in the world, but i don't see any grounds for declaring it incorrec.t

Wrong: This model explains all known subatomic particles, SOME OF THEM WHICH WERE only recently discovered.

1/
in formal written english (as presented on the gmat exam), you don't use "which" without a comma; in those situations, you use "that" instead.
(note: this does not apply to "of which", "from which", etc. -- those things may either follow a comma or not follow one.)

2/
the problem here isn't the "were" by itself; it's the juxtaposition of "them" and "which".
even if you change "which" to "that" (as discussed in the point above), you can't put both of those words into the same sentence together, because they're fighting with each other -- they're both trying to fulfill exactly the same grammatical role:
some of ____
you can fill in the blank with "which", OR you can fill it in with "them". not both.

by the way, make sure you know how each of those words would be used alone:

* ... all known subatomic particles, some of which were only recently discovered
("some of which" acts grammatically like "which" -- it has to be the subject of a verb.)

* ... all known subatomic particles, some of them only recently discovered
(if you want to google this type of construction, it's called an "absolute phrase". make sure you aren't thinking about grammatical terms when you're solving the problems (!!), but that will help you look up more examples.)

Wrong: This model explains all known subatomic particles, SOME OF WHICH only recently discovered.

"which" must be the subject of the verb that follows it. so, this sentence is illogical in 2 ways:
1/
it implies that the particles themselves discovered stuff (!),
and
2/
you can't use "discover" without an object.

it's incorrect to state that the particles discovered -- you have to state that the particles were discovered.

Questions Two:

In the above sentence, can we effortlessly say that the antecedent of "it" is "the agency", because clauses starting with "THAT" are parallel and they should be structurally similar.
Thanks,
Kiran

"pronoun ambiguity" is not something you should be thinking about. if a pronoun works (= it actually stands for a noun, and it matches the noun in terms of singular/plural), and it's obvious which noun it should stand for, then it's fine.

[RonPurewal]

adding one question:

remember -- when you add stuff to a thread, it goes back to last place in the reply queue (because we reply to posts strictly in order from oldest to newest).

The model explains all known subatomic particles, some of them were only recently discovered :- should also be correct? Because particles are discovered by someone not discovered by themselves.

nope -- that's a run-on sentence.
you've got 2 complete sentences, stuck together with only a comma. not allowed.
(the blue stuff is a sentence all by itself; so is the green stuff.)

In the similar lines,
This model explains all known subatomic particles, SOME OF THEM only recently discovered.
This model explains all known subatomic particles, SOME only recently discovered.

Why helping verb"were" is not present in above 2 sentences. They were not discovered themselves.

Please explain..

Thanks[/quote]

for more examples of this type of thing, google the term "absolute phrase".
if you have the OG verbal supplement, check out problem #19 (about chinese characters -- i can't reproduce the problem here), in which a similar construction is used.

[RonPurewal]

adding one question:

The model explains all known subatomic particles, some of them were only recently discovered :- should also be correct? Because particles are discovered by someone not discovered by themselves.

In the similar lines,
This model explains all known subatomic particles, SOME OF THEM only recently discovered.
This model explains all known subatomic particles, SOME only recently discovered.

Why helping verb"were" is not present in above 2 sentences. They were not discovered themselves.

Please explain..

Thanks

if you add "were" to these, you'll get run-on sentences (i.e., things that are wrong).
see the post with the blue and green coloring -- same idea.

[rte.sushil]

After reading the above text,

i summarized my doubt and the confusion with the sentence:

"How to say that some of them is object: no use of 'were' is required
and some of which is subject":-> were is required
____________________________________________
In other words:

"which" must be the subject of the verb that follows it. so, this sentence is illogical in 2 ways:
1/
it implies that the particles themselves discovered stuff (!),
and
2/
you can't use "discover" without an object.

"which" must be the subject of the verb and
some of them only recently discovered-> absolute phrase in which some of them will be acting as an object of the verb discover.

______________________________________________

TO understand the summary in detail: refer below

Quote:
The model explains all known subatomic particles, some of them were only recently discovered :- should also be correct? Because particles are discovered by someone not discovered by themselves.

nope -- that's a run-on sentence.
you've got 2 complete sentences, stuck together with only a comma. not allowed.
(the blue stuff is a sentence all by itself; so is the green stuff.)

Question:
"some of them were only recently discovered" has become a complete sentence then why can't below sentences be complete sentences:
"Some of which only recently discovered"
"Some of which were only recently discovered" (e.g. passive voice)
"some of them only recently discovered" (e.g. as an active-voice)

So the entire confusion is : why to take "some of them" as object and " some of which" as subject OR not considered similarly to use in a sentence.

[Willy]

Question:
"some of them were only recently discovered" has become a complete sentence then why can't below sentences be complete sentences:
"Some of which only recently discovered"
"Some of which were only recently discovered" (e.g. passive voice)
"some of them only recently discovered" (e.g. as an active-voice)

So the entire confusion is : why to take "some of them" as object and " some of which" as subject OR not considered similarly to use in a sentence.

Second one is complete sentence, I believe. Other 2 can't be as there is no verb in those sentences. "discovered" in both of these examples is working as participle not as verb.

[tim]

The whole question of whether these examples are "complete sentences" seems to miss the point: what's most important is the role that each part plays in a sentence and whether it is being used correctly. This of course cannot be done in isolation, so asking questions about portions of sentences devoid of context is often not productive. If you have specific and relevant questions to ask that will actually help your understanding of how to solve SC problems, by all means share them and we'll be glad to help you.