the following problem is posted on beatthegmat and gmat club forum but no full explanation is given. Ron, Manhantan experts, pls help.

The question is when to use "to do" and when to use "for doing"
(the first question seems to be from gmatprep. the second from og). I will check whether the first question is from gmatprep. If it is, I will post this problem in the subforum "gmatprep".

New genetic evidence-together with recent studies of elephants' skeletons, tusks, and other anatomical features-//provide compelling support for classifying//Africa's forest elephants and its savanna elephants as separate species.


C.provides compelling support to the classification of

D.provides compelling support for classifying

E.provides compelling support to classify

Q 11, og 11

[Moderator's Note: OG is a banned source; it is against copyright law to post OG questions anywhere on the web.]

Here's the way C, D, and E are used in this first problem:

(C) Evidence provides support to an idea.
(D) Evidence provides support for an idea.
(E) Evidence provides support (to classify) something.

D is correct here because you want to provide support for an idea- "classifying the two elephants as different species."

C- If you provide support to X, you are giving something to X: I provide support to my mom (I give something to my mom).

E- Is idiomatically incorrect. By placing a verb after the preposition "to" you create a confusing sentence where it looks like "to classify" is being used as a verb. You wouldn't provide support to donate, but rather provide support to (the idea of) donating.

_________________
Joe Lucero
Manhattan GMAT Instructor

I learn gmat to take MBA

is correct sentence

I learn gmat for taking MBA

is wrong sentence.

why D is correct in the following?
New genetic evidence-together with recent studies of elephants' skeletons, tusks, and other anatomical features-//provide compelling support for classifying//Africa's forest elephants and its savanna elephants as separate species.


C.provides compelling support to the classification of

D.provides compelling support for classifying

E.provides compelling support to classify

E is wrong because E means " evidence provide support in order that evidence classify". This is not logic. the logic/intended meaning is "evidence provide support for someone to classify" . Am I correct in this point ?

Can I say that " to do " is used to show purpose of the subject of the first verb but "for doing " is used to show purpose of other persons ??? I am confused,

Yes. It doesn't say a specific person will classify, but rather that support for classifying these two species separately. But your sentence makes logical sense.



Different issue altogether. To + verb = the infinitive form of a verb. To + noun = prepositional phrase.

_________________
Joe Lucero
Manhattan GMAT Instructor