Can someone elaborate why idioms are important to learn? I have a list of idioms to study for and I just don't understand the purpose of studying them. Please enlighten and show me the way. Thank you!

Hello,
I would like to discuss my case.I am still not good with idioms although I am also in a learning process like you and I am not a native english speaker(so I cann't actually depend on my ears!!)

When you learn all the concepts(like subject-verb Agreement,tenses,moods modifiers etc) and if you start solving questions, you will still get stuck with lots of questions which actually require idioms.
Because idioms are not sometimes grammatically correct yet they exist in Standard English,this makes task difficult to apply the concepts of grammar.

Hope this makes sense to you now that why idioms are so Important!

BlindVision wrote: Can someone elaborate why idioms are important to learn?

I can tell you from my experience that idioms are extremely important.

My verbal score was very bad due to SC (v25). I just scanned over the main concepts in my preparation most of which I remembered from my English classes in high school. I am not a native speaker, so I had a lot of trouble with idioms and mainly skipped that part (BAD IDEA!).

In the real exam I realized that even if the original error was not idiomatic, in most cases the answer choices correcting the original error contained idiomatic expressions. Therefore idioms are necessary for almost all SC questions.

For the retake I'll definitely study idioms, so I won't miss that one again!

Probably you don't have to study idioms if you are a native speaker, but maybe even native speakers are not familiar with all idioms (could depend on region, social environment, etc.)