The Chicago and Calumet Rivers originally flowed into the

[divineacclivity]

Ok, I'll try & stick to the gmat sentence unless it is getting v tough to understand a rule without taking an example & I can't really find one from gmat itself.

1. So, my question here is if "by constructing" is always wrong or is it wrong (the way it's been used in option B) i.e. because "by constructing" makes it seem like the action (construction) is done by the subject i.e. "Rivers".

2. Would this usage "by constructing" be correct if a sentence is supposed to convey that the action ("by constructing" in this example) is done by the subject (rivers in this example)

option B for your reference:
B) Rivers had originally flowed into the St. Lawrence by way of Lake Michigan, but they have been redirected by constructing

thanks in advance

[RonPurewal]

1. So, my question here is if "by constructing" is always wrong or is it wrong (the way it's been used in option B) i.e. because "by constructing" makes it seem like the action (construction) is done by the subject i.e. "Rivers".

the latter

2. Would this usage "by constructing" be correct if a sentence is supposed to convey that the action ("by constructing" in this example) is done by the subject (rivers in this example)

well, that's one requirement, but not the only one.
"by VERBing" should also describe the way in which something is done, or the means by which something is accomplished.
e.g., james will increase his oxygen capacity by swimming underwater sprints.

in other words, it can't just be used for any random action that happens to have the correct subject; you also need to have the correct relationship in context.

[divineacclivity]

Ron, you just always know exactly what the other person's confusion is. thank you very much.

May I please ask a follow up question?
If I have a sentence like the following one (analogous to option B: Rivers have been redirected by constructing..)

This money has been collected by begging.
Does the sentence wrongly conveys that begging is done by the money? Is the sentence absolutely wrong?
should "by begging" be replaced by "through begging"?

Option B for your reference:
B) Rivers had originally flowed into the St. Lawrence by way of Lake Michigan, but they have been redirected by constructing

thanks in advance.

[RonPurewal]

the problem with that analogy is that there's no dedicated form of "begging".
i.e.
constructing <--> begging
construction <--> begging
so, your sentence is right, but only because there's no form of "begging" that's like "construction".
if there were a word like "beggage" or "beggation" or whatever, then that sentence wouldn't work.

[RonPurewal]

the problem with that analogy is that there's no dedicated form of "begging".
i.e.
constructing <--> begging
construction <--> begging
so, your sentence is right, but only because there's no form of "begging" that's like "construction".
if there were a word like "beggage" or "beggation" or whatever, then that sentence wouldn't work.

as a more workable analogy, consider "inspecting"/"inspection".

you can discover this result by inspecting all of the possible cases.
--> correct

this result can be found by inspection.
--> correct

this result can be found by inspecting.
--> nope

[divineacclivity]

I couldn't ask for a better explanation, Ron. Thank you so much.

[divineacclivity]

the problem with that analogy is that there's no dedicated form of "begging".
i.e.
constructing <--> begging
construction <--> begging
so, your sentence is right, but only because there's no form of "begging" that's like "construction".
if there were a word like "beggage" or "beggation" or whatever, then that sentence wouldn't work.

as a more workable analogy, consider "inspecting"/"inspection".

you can discover this result by inspecting all of the possible cases.
--> correct

this result can be found by inspection.
--> correct

this result can be found by inspecting.
--> nope

Just one more thing here:
So, "through" and "by" do not have a significant difference in the context of examples given in your post above or even in the context of the option in the question. Do I understand that right?
thanks in advance.

[RonPurewal]

Just one more thing here:
So, "through" and "by" do not have a significant difference in the context of examples given in your post above or even in the context of the option in the question. Do I understand that right?
thanks in advance.

well, i'm thinking through a bunch of examples, and i don't think it's acceptable to put "through" in front of -ing forms; it seems that "through" is only acceptable in front of the noun form. (for instance, you could find something out through experimentation, but not through experimenting with xxxxx or through conducting experiments.)

more importantly, though, the chance that the gmat will actually test this sort of thing is pretty much zero.

[divineacclivity]

ok, thank you very much.

1. so, "through" doesn't look good in front of simple gerunds, even in front of complex gerunds?

2. by can be put in front of action nouns as well as gerunds, right?

thanks in advance

[RonPurewal]

So, "through" and "by" do not have a significant difference in the context of examples given in your post above or even in the context of the option in the question. Do I understand that right?
thanks in advance.

in this context, not really. (even when there is a difference, it's far too subtle to be tested on this exam.)

[RonPurewal]

ok, thank you very much.

1. so, "through" doesn't look good in front of simple gerunds, even in front of complex gerunds?

2. by can be put in front of action nouns as well as gerunds, right?

thanks in advance

sorry, but i don't really know the grammar terms here. can you post some examples to illustrate what you are asking?
thanks.

[divineacclivity]

Ok, I'll pick example from your post above :)

1. You could find something out through experimentation - CORRECT
2. You could find something out through experimenting with XXXXXX - INCORRECT
3. You could find something out by experimenting with XXXXXX - CORRECT
4. You could find something out by experimentation - CORRECT???
3. You could learn something out through the construction of such science models - CORRECT???

thank you very much, Ron. I always look forward to getting replies from you because they're very nicely written and very informative.

[tim]

your analysis of all these examples looks fine. the main takeaway here is that #2 is wrong as you've noted. remember the biggest mistake you have to avoid on SC is counting something wrong when it really isn't, so unless you're SURE an answer choice is wrong on a given point just leave it and find some other basis for making your decision..

[ikuta.yamahashi]

Dear instructor:

Two questions for me.
1. According to MGMAT sc guide, "Use by only for the actual doers of the action. Use through or because of when you want to describe any instrument or means, which might be an awkward or nonsensical subject in active voice. "

It confuses me alot, because in your examples above
this result can be found by inspection.
--> correct
inspection is not the doer of the action of discover.
could you help me to slove the paradox?
2. In below sentence from prep, the right choice use by doing/buring/replacing with the subject emissions; however, it seems emission cannot burn or replace anything. I am not intent to challenge the OA, just for confirm the usuage of by doing.

The majority of scientists believe that to reduce and stabilize atmospheric concentrations of carbon dioxide, emissions must be cut at the source by burning fossil fuels more efficiently and, in some cases, by replacing fossil fuels altogether with alternatives such as hydrogen fuel cells
Yama

[jlucero]

Dear instructor:

Two questions for me.
1. According to MGMAT sc guide, "Use by only for the actual doers of the action. Use through or because of when you want to describe any instrument or means, which might be an awkward or nonsensical subject in active voice. "

It confuses me alot, because in your examples above
this result can be found by inspection.
--> correct
inspection is not the doer of the action of discover.
could you help me to slove the paradox?
2. In below sentence from prep, the right choice use by doing/buring/replacing with the subject emissions; however, it seems emission cannot burn or replace anything. I am not intent to challenge the OA, just for confirm the usuage of by doing.

The majority of scientists believe that to reduce and stabilize atmospheric concentrations of carbon dioxide, emissions must be cut at the source by burning fossil fuels more efficiently and, in some cases, by replacing fossil fuels altogether with alternatives such as hydrogen fuel cells
Yama

1. But someone has to be inspecting for the result to be found. Inspection isn't the doer, but the person who is the doer is using inspection. Likewise, "The answer is revealed by pushing a button" The doer in this case is not a button, but the person pushing that button.

2. Same thing in this sentence. The subject is ambiguous (we all have to burn ff more efficiently and replace ff altogether), but it's this ambiguous subject who is doing the action.

I'm not sure where in the SC guide you are reading this difference, but the use of by/through is more of a meaning issue to express whether something is the means or the end. Here's an idiomatic-ly correct illustration of when to use by/through:

We will win the war by force. (force is what will win the war)
We will win the war through diplomacy. (diplomacy will not by itself win the war, but will be a tool we will use to win the war)

Here's some more:
We will win the war...

by bombing their army. (end)
through superior technology. (means)
by capturing their capitol. (end)
through media. (means)