Galileo did not invent the telescope, but on hearing, in 1609, that such an optical instrument had been made, he quickly built his own device from an organ pipe and spectacle lenses.
A. Galileo did not invent the telescope, but on hearing, in 1609, that such an optical instrument had been made, he
B. Galileo had not invented the telescope, but when he heard, in 1609, of such an optical instrument having been made,
C. Galileo, even though he had not invented the telescope, on hearing, in 1609, that such an optical instrument had been made, he
D. Even though Galileo did not invent the telescope, on hearing, in 1609, that such an optical instrument had been made,
E. Even though Galileo did not invent the telescope, but when he heard, in 1609, of such an optical instrument being made, he
OA is A.
Could you tell me the structure in A?
Thanks

Galileo did not invent X, but on hearing that (someone did invent X), he built his own device.

I did not invent the GMAT, but on hearing that such a test had been made, I quickly developed my own practice GMAT software. :)

B uses wrong tense (had not invented), wrong idiom (heard... of), and wrong tense again (having been made)
C is not a complete sentence (it basically says: Galileo, on hearing, he quickly built...).
D changes the meaning - he didn't build a telescope "even though" he didn't invent it. "Even though" indicates some kind of cause-effect connection. The original sentence is just telling us - he wasn't the inventor but he did build one soon after its invention.
E repeats multiple errors already discussed above

_________________
Stacey Koprince
Instructor
Director of Online Community
ManhattanGMAT

Hi Stacey..


B -why is had not the correct tense in B - isnt the action before he built his own.... also whats wrong with having been
C - G on hearing that X happened,he did Y - why is this not complete ..

please help... many thanks

B: We want the action of making the first telescope to precede the action "he heard," so the past perfect passive "had been made" is necessary to show that sequence. "Having been made" is present perfect, the wrong tense.

That issue aside, if we look at just "Galileo had not invented the telescope but he quickly built his own device," I would say it's technically fine, but unnecessarily complicated. Compare it to "Galileo did not invent the telescope but he quickly built his own device." In this sentence, there's no confusion about the order of the events.

C: If you take out the modifying elements, the sentence reads "Galileo he quickly built his own device." Two subjects? Not a good sentence.

I think we can't change to "Galileo had not invented the telescope but he quickly built his own device"
because even now Galileo still not invented, he only built it. The past perfect shall use when we know the ending point.
Does I correct?

2. Rey wrote:
B: We want the action of making the first telescope to precede the action "he heard," so the past perfect passive "had been made" is necessary to show that sequence. "Having been made" is present perfect, the wrong tense.

I dont understand why "Having been made" is present perfect?
Can it be the short form when we write "X that had been ... " and we shorten it by changing to "X having been"

HI Stacey,

I don't see the different meanings between a sentence using "even though" and a sentence using "but"
Could you use this prep question as an example to illustrate the difference between "even though" and "but"?
Thanks in advance.

I didn't articulate this as well as I could have.

Part of it is the word change and part of it is the placement change in the sentence.

I did not invent the GMAT, but on hearing that such a test had been made, I quickly developed my own practice GMAT software.

Even though I did not invent the GMAT, on hearing that such a test had been made, I quickly developed my own practice GMAT software.

The first one means: I didn't invent X, but I did invent something based on X. The implication here is that I'm just letting you know I didn't invent it, almost as an aside (extra piece of info).

The second one means: Even though I didn't invent X, I was still able to invent something based on X. The implication here is that there's some expectation that I should not have been able to invent something based on X because I didn't invent X myself - something like that. But despite the handicap that I didn't invent X, I was still able to invent something based on it. I overcame the difficulty! :)

_________________
Stacey Koprince
Instructor
Director of Online Community
ManhattanGMAT

Stacey Koprince,

thanks for your great answer.

I like this example you "invent" in the notes although you are not invented the GMAT,

haha !

Hi,

Wish to know please for the future , is 'heard of' an incorrect idiom as Stace pointed out in option B here.

Many Thanks.

-Regards,
Girish

I would not say that "heard of" is wrong on its own. However, it would need to be followed by a simple noun. For example, I have heard of the band The Strokes. In this sentence, however, the "heard of" is followed by a clause. As a result, "heard that ....." is what we want.

I observed another split in this question..

have ....made, he quickly
.....made, quickly ..

Which way should I go if this is my first split ?

In that case, you should look back before the information set off by commas, to see if there is indeed a subject for the words "quickly made." In the two cases where we have ", quickly made," there is not subject; thus, these choices are incorrect.

one good explanation for this Q here:

http://www.beatthegmat.com/gmat-prep-ga ... 34256.html

good find.