The results of the company’s cost-cutting measures are evident in its profits, which have increased 5 percent during the first 3 months of this year after falling over the last two years.

It is the correct sentence in OG12.

Can I modify the sentence to :

The results of the company’s cost-cutting measures are evident in its profits that have increased 5 percent during the first 3 months of this year after falling over the last two years.

is my sentence right?

In addition, I want to ask a question:
Please tell me the difference between the clause leading by "that" ,such as the second sentence listed above, and the non-restriction clause leading by "which" , such as the original sentence listed above.

Thanks very much!

IMPORTANT NOTE:
the difference between “restrictive” and “nonrestrictive” modifiers has never been the basis of an official problem. therefore, it is almost certainly not worth worrying about.

with that said, here's a very basic summary:
* modifiers that are set off by commas (known as “nonrestrictive” modifiers) don't narrow the possibilities for what they are modifying. instead, they simply give more, or more descriptive, information about that thing.
* modifiers that are not set off by commas (known as “restrictive” modifiers) narrow the possibilities -- that is, they specifically exclude things that aren't described by the modifier. therefore, in this case it's assumed that there are some things that satisfy the modifier and others that don't, and that the sentence is only intended to refer to the ones that do.

for instance:
open the third door, which is green --> in this case, you just have to open the third door (i.e., “the third door” is a sufficient description by itself). the modifier just gives additional helpful information.

open the third door that is green --> this means that you need to open the third one among all doors that are green (i.e., excluding other doors). this door may in fact be the 500th door, but it's the third green one.



no, because that would imply that there were some other profits that didn't increase in this way (thus requiring this kind of modifier to narrow down the possibilities). that's not a reasonable meaning -- the sentence is clearly talking about the company's profits as a whole -- so you can't write the sentence that way.



see above -- but remember that this kind of difference has never actually been dispositive in an official problem.