pallavichsk wrote:
GMATNinja daagh VeritasKarishma generis egmat MartyTargetTestPrepEven I have the same question. It will be great if any of the experts can kindly help on this.
How are may and perhaps different here? Why can't we use as well instead of also?
Sorry for our ludicrously delayed response,
pallavichsk!
First, let's take another look at the parallelism in (B) and (E).
In (E), we get, "Indoor air pollution (1)
can threaten the health... and (2)
may also
impair the quality." As explained in
this post by
AjiteshArun, "may" is a modal (as is "can"). Ignoring the "also," both items in the list follow the pattern, "[
modal] + [
infinite form (without the "to")]. That's as parallel as you can get.
In (B), we get, "Indoor air pollution (1)
can threaten the health... and (2) perhaps as well
impairs the quality." Because "can impairs" is wrong, we know the "can" doesn't apply in the second verb phrase.
Is the parallelism
wrong in (B)? Probably not. But the parallelism is definitely better and clearer in (E). So there's one vote in favor of (E) vs (B).
Now, are there clear cut rules for when you should use "can" vs. "may" vs. "perhaps"? Definitely not, and what follows is not an invitation to invent any. With that disclaimer in mind, I'd argue that "may" is
probably a bit more appropriate than "perhaps" given the context:
First, consider this basic example:
"Drinking coffee can increase anxiety."
This sounds like a pretty established relationship. We KNOW (or we're fairly confident) that increased anxiety is POSSIBLE if someone drinks coffee. Will that happen every time someone drinks coffee? No. Whether it does presumably depends on the details of each particular case.
In other words, we aren't sure that it will happen in each unique instance, but we are fairly sure that the possibility exists.
Now let's change it to "perhaps":
"Perhaps drinking coffee increases anxiety."
Now it sounds like we are less sure that the possibility exists -- maybe drinking coffee increases anxiety, and maybe it doesn't. This might be a reasonable theory, but it doesn't seem like we have much evidence one way or the other.
Finally, let's try with "may":
"Drinking coffee may increase anxiety."
This one seems somewhere in between the previous two. Maybe we have SOME evidence that there's a relationship between drinking coffee and increased anxiety, but not even to conclude that relationship exists.
Also, there's a subtle meaning issue with "perhaps as well impairs":
- Remember, "as well" pretty much means "in addition to " here, so we have, "Indoor air pollution can threaten the health... and perhaps in addition impairs the quality..."
- So what does the "perhaps" modify? As well (or "in addition")? (So it MIGHT be in addition?) Or does "perhaps" modify the verb "impairs"? (SO it MIGHT impair?) It isn't clear.
- (E) avoids that clarity issue entirely by sticking to the nice, parallel structure described above.
Again, is (B) terrible? No. But compared to (E), it has a few disadvantages without any apparent advantages. The parallel structure in (E) makes the meaning a bit more clear, so (E) is the better choice.
I hope that helps!