Industrialization and modtern methods of insect control have

[RonPurewal]

I thought that with coordinate conjuctions such as AND, BUT, OR....you should have the same tense!!

nope. it depends on context. if the context clearly indicates the necessity of using different tenses, then you have to use different tenses.

for instance:
he has made the same mistake over fifty times, and he will make it fifty more times before he learns his lesson.
perfectly grammatical tense.
given the context - the first half is talking about events that have happened in the past, and the second is talking about events that are going to happen in the future - it should be clear that we can't use the same tense.

hope that helps

[cesar.rodriguez.blanco]

Thanks!

[rohit21384]

Hi tutors,

Can I know why d is wrong?

d. but introducing some 100,000 dangerous chemical pollutants at the same time that have

Thanks!

"but" is a coordinating conjunction. it's in the same category as "and" and "yet".
this type of conjunction demands PARALLELISM between the things that appear on either side of it.

that doesn't happen in choice (d).
the left hand side is "have improved...", which is an actual VERB.
the right hand side is "introducing...", which is NOT a verb (it's just a participle).

these are not parallel.

you don't have to have 100% PERFECT parallelism - i.e., the verbs don't have to be in the same tense (and indeed context may demand that they not be in the same tense) - but, if one part is an actual verb, then parallelism demands that the other part be an actual verb, too.

--

"while" is a subordinating construction, not a coordinating one, so it doesn't have the same strict parallelism requirements as does "but".

Industrialization and modtern methods of insect control have improved the standard of living around the globe ..............................................gone virtually unregulated since they were developed more than 50 years ago.

b. while at the same time introducing some 100,000 dangerous chemical pollutants that have


My question here is that in the correct answer we have following construction:
main clause followed by subordinator + present participle(adverbial modifier modifying the main clause).

and hence main clause is not followed by a subordinating clause.

What I am getting from here is that subordinator need not be a clause ?
I thought that subordinating construction following the main clause has to be clause.
Instructors - can you please elaborate on this issue with some examples.

isnt this construction similar to main clause followed by adverbial modifier...though here we have used "while at the same time" to show contrasting result of the main clause..........please see below

Industrialization and modern methods of insect control have improved the standard of living around the globe (while at the same time )introducing some 100,000 dangerous chemical pollutants that have gone virtually unregulated since they were developed more than 50 years ago.

Ron need your help on this thing

[RonPurewal]

What I am getting from here is that subordinator need not be a clause ?
I thought that subordinating construction following the main clause has to be clause.
Instructors - can you please elaborate on this issue with some examples.

hi -

unfortunately, some "subordinators" require clauses all the time, but others don't. idiomatic usage at its finest.

even more frustrating is that many of the subordinators that don't require clauses are very similar to those that do.

for instance:
"even though" MUST be followed by a clause.
"although", however, can be followed by an adjective or adjective phrase: james, although bigger than many of the other players, is one of the fastest men on the team.

so you just have to memorize which ones can do which.

in this case, you've just learned that "while" can be followed by an -ing participle. (it can also be followed by an adjective or adjective phrase.)

[agha79]

English is not my first language but for this problem I scratched out A & B right away assuming that the word "While" and "at the same time" mean the same and is redundant. What is the rule that I need to know to avoid this mistake in the future if any?

[RonPurewal]

English is not my first language but for this problem I scratched out A & B right away assuming that the word "While" and "at the same time" mean the same and is redundant. What is the rule that I need to know to avoid this mistake in the future if any?

it's true that the conjunction "while" can be used to signal simultaneity, but it's more often used to signify contrast.
e.g., while my friends studied six hours per week, i only studied half an hour per week.

in any case, you should just learn this one as an isolated truth (the same way you'd learn any other idiom).

[salman30]

you don't have to have 100% PERFECT parallelism - i.e., the verbs don't have to be in the same tense (and indeed context may demand that they not be in the same tense) - but, if one part is an actual verb, then parallelism demands that the other part be an actual verb, too.

[/quote]

Can you explain this point about parallelism?
I thought that with coordinate conjuctions such as AND, BUT, OR....you should have the same tense!![/quote]

I know "while at the same time " is correct in this sentence (as it is in the correct choice). However, I thought if we just use "while" it will represent the parallel event anyway and "at the same time" shouldn't be necessary here and hence I chose C. Can you please advise ?

[tim]

There's really nothing to explain about that point of parallelism; it is what it is. As for the other question, don't eliminate an answer just because you would prefer to see a different wording. Unless the wording as written is wrong, keep the answer choice and try to find mistakes in the other choices..

[salman30]

you don't have to have 100% PERFECT parallelism - i.e., the verbs don't have to be in the same tense (and indeed context may demand that they not be in the same tense) - but, if one part is an actual verb, then parallelism demands that the other part be an actual verb, too.

[/quote]

Can you explain this point about parallelism?
I thought that with coordinate conjuctions such as AND, BUT, OR....you should have the same tense!![/quote]

while at the same time introducing some 100,000 dangerous chemical pollutants that have

WHILE normally represent the parallel events anyway. is "at the same time" redundant in the sentence above ? Please advise.

[ChrisB]

Hi Cesar,

Tim's point is just that sometimes verb tenses must change for meaning purposes. Check out this sentence below.

Although I WORKED hard on my project, I AM worried that my teacher will fail me.

Here the two verbs worked and am are parallel but in different tenses. That is because the sentence would take on a whole new meaning if I tried to force in parallelism using WAS instead of AM in the second part of the sentence:

Although I WORKED hard on my project, I was worried that my teacher will fail me.

Now that sentence doesn't make any sense because the two actions "worked" and "was" occurred at the same time. It's clear that the worry didn't start until after the project was completed so the sentence MUST use different tenses for the two verbs.

In this case, the parallelism holds because the two verbs are parallel to one another though the tense is different.

When you think about it, nearly everything that we discuss in the verbs chapter of the SC guides comes down to parallelism :)

Thanks,
Chris

[vjsharma25]

I have one query in answer choice "C",which is wrong.
1. Does ",which have" points to the "100,000 dangerous chemical pollutants "?
If it is so then in "gone virtually unregulated since they were developed more than 50 years ago." does the highlighted "they" refers to "chemical pollutants" or does it still refers to the "methods"?

[dmitryknowsbest]

I don't see "which have" in any of the choices.

"They" refers to methods. Although we do have more than one plural noun in the sentence, the structure of the sentence makes the antecedent clear. The chemicals have gone unregulated since they were developed. Notice that in the correct version, the word "they" is only used this one time.

[igordudchenko]

remember the order of the 3 'c's in the hierarchy of sentence correction: 1, correctness; 2, clarity; 3, concision.
these are in order.
DO NOT think about ambiguity before you resolve the issues that are concretely right vs. wrong.
if you follow these steps in the correct order, you won't have to decide between two or more legitimate meanings, although you still might have to
* eliminate absurd meanings, or
* choose choices that uphold the meaning of an unambiguous original sentence over altered versions.

at risk of being terribly redundant, though, one more time for the road: if the original doesn't make the author's intent clear, and the answer choices display alternative meanings (both of which are reasonable), then the issue should resolve itself when you eliminate the choices that are just plain wrong from a linguistic standpoint

Golden words, Ron. I am re-reading SC forum and I see too many students arguing about hypothetical situations. I believe the correct approach to SC is questioning correctness of each answer choice instead of justifying why these choices are true. At the end of the day, the method is called POElimination, not POJustification.

[jnelson0612]

igor, excellent observation! I love how you put that.

[muralik.abm]

Industrialization and modtern methods of insect control have improved the standard of living around the globe while at the same time they have introduced some 100,000 dangerous chemical pollutants, having gone virtually unregulated since they were developed more than 50 years ago.

a. while at the same time they have introduced some 100,000 dangerous chemical pollutants, having

"having" (the participle) modifies the subject (they - I&M methods) of the preceding clause --- WRONG.
100,000 dangerous chemicals are gone virtually unregulated.

b. while at the same time introducing some 100,000 dangerous chemical pollutants that have

CORRECT

c. while they have introduced 100,000 dangerous chemical pollutants at the same time, and have

it is wrong not only in grammar, but also in the meaning.

the text "introduced 100,000 dangerous chemical pollutants at the same time" means that ALL the 100,000 pollutants are introduced at the same time. But the intended meaning of the sentence is these pollutants are introduced as a side effect/direct effect of the insect control. ---- WRONG

d. but introducing some 100,000 dangerous chemical pollutants at the same time that have

it is wrong not only in grammar, but also in the meaning.

the text "introduced 100,000 dangerous chemical pollutants at the same time" means that ALL the 100,000 pollutants are introduced at the same time. But the intended meaning of the sentence is these pollutants are introduced as a side effect/direct effect of the insect control. ---- WRONG

e. but at the same time introducing some 100,000 dangerous chemical pollutants, having

The clause after BUT is not an independent clause -- Sentence fragment --- WORNG.

Masters, please correct me if i am wrong.