It might require some
unlearning or
deprogramming. I've had success in the past with someone experienced in another language, and just going through with them in a manner that has them come up with a programming task (or
idiom.) in the their strong language; then showing them the Perl
idiom. General concepts about dynamic languages in your case sounds like it should not be a barrier. This relies on them being proficient with another language (here Python); and the stronger the better.
Another thing that comes to mind that might be helpful is, Rosetta Code.