issues with idiomatic expressions

[kpzzle_naypi]

hi!
Good day!
I am currently writing a paper on the problems esl speakers face with idiomatic expressions. I just want to ask if ever there are any certain research studies as to why it takes them quite a while to decipher the meaning, even with simple phrasal verbs used in every day conversations..
Or if there is none, as a teacher, what can you say about this.
I am a second-language speaker myself, and I know can attest that it takes a while,epecially if you're not used to using it. I just want a little back-up on this for my research paper..thank you so much!I hope you can answer my question asap.
more power!

[Tdol]

Try here: http://scholar.google.com/scholar?hl...ge&btnG=Search